RESEARCH UPDATES-01

We start publishing latest research findings in sericulture and related fields for the benefit of researchers and students in the field. Our intention is to help you by reducing your efforts in finding latest research information. We painstakingly hunt for articles and present before you. Make it a habit to check this site once a week, you get it all here. To begin with the information is provided under four categories viz. Mulberry, Silkworm, Non mulberry sericulture and Silk. Title, details of publication and a link to the full article are provided on a weekly basis. Each weekly posting of RESEARCH UPDATES will be linked.
In a few cases you may need subscription to the journal to access the full article. We hope it will be of use to all subscribers of ‘the silkworm’. We are keen to receive your comments.

A. Mulberry
1. Light, Temperature, Seed Burial, and Mulch Effects on Mulberry Weed (Fatoua villosa) Seed Germination
GINA M. PENNY and JOSEPH C. NEAL
Weed Technology Volume 17; Issue 2 (April 2003) pp. 213–218
Abstract
Fatoua villosa (mulberry weed) is a new and invasive weed of container nurseries and landscapes in the southeastern United States. Studies were conducted to determine the effects of light, planting depth, mulch depth, and temperature on mulberry weed seed germination and seedling emergence. Light stimulated mulberry weed seed germination, with less than 5% of seeds germinating in the dark compared with 48 to 60% germinating in the light. In all emergence studies, the highest number of seedlings emerged when seeds were placed on the soil surface, with emergence decreasing as planting or mulch depth increased. Planting depths of 1.8 cm or mulch depths of 3.7 cm reduced mulberry weed emergence by 90%. These data suggest that mulch would control mulberry weed effectively. To study the effects of temperature on germination, two seed batches collected locally in October 1998 and August 1999 were used. Maximum germination of seeds collected in 1998 occurred at 25 C, with germination decreasing at higher temperatures and no germination at lower than 15 C or over 40 C. For seeds collected in 1999, maximum germination occurred from 19 to 29 C, with germination decreasing with temperatures above 29 C or below 19 C. At temperatures of 15 and 42 C germination, percentages were 71 and 11%, respectively. Seedlings germinated at 15 C developed slowly but otherwise appeared normal. For both seed lots, seedlings were stunted and chlorotic at 38 C. That mulberry weed seed germinated over a wide range of temperatures suggests its potential to emerge throughout most of spring, summer, and autumn in the southeastern United States.
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1614%2F0890-037X%282003%29017%5B0213%3ALTSBAM%5D2.0.CO%3B2
2. Micromorphological Characterization of Ten Mulberry Cultivars (Morus spp)
Magda Biasiolo, Maria Teresa Da Canal, and Noemi Tornadore(Biology Department, Geobotany Section, Padua University, V. G. Colombo 3, 35121 Padova, Italy; E-mail: tornado@civ.bio.unipd.it)
Economic Botany Volume 58, Issue 4 (December 2004)
Abstract
The micromorphological features of the vegetative and reproductive structures of ten mulberry cultivars grown at the Specialized Sericultural Section of the Agricultural Zoology Experimental Institute of Padua, northeastern Italy, were examined by SEM in order to determine the charactetistics that were the most valuable taxonomically. The observed specimens (leaves, flowers, seeds, and pollen grains) showed micromorphological differences regarding leaf hairiness, quantity of waxes, quality of epidermis cuticle and tepal hairiness. The effects of differing environments in altering the floral sex ratios of this basically monoecious group of plants were also investigated. However, no significant differences between the micromorphology of the seeds and the pollen grains of these selected cultivars were detected. The authors are hopeful that the information gained in this study may prove useful in the future creation of an exhaustive and final catalogue “descriptor” of cultivated varieties belonging to the genus Morus L.
Keywords: White mulberry, cultivars, SEM, leaf, flower, seed, pollen grain micromorphology
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1663%2F0013-0001%282004%29058%5B0639%3AMCOTMC%5D2.0.CO%3B2
B. Silkworm
1. Developmental Profile of Annexin IX and its Possible Role in Programmed Cell Death of the Bombyx mori Anterior Silk Gland
Yu Kaneko, Keiko Takaki, Masafumi Iwami, and Sho Sakurai
Zoological Science Volume 23, Issue 6 (June 2006) pp. 533–542
Abstract
During pupal metamorphosis, the anterior silk gland (ASG) of the silkworm, Bombyx mori, undergoes programmed cell death (PCD), which is triggered by 20-hydroxyecdysone (20E). Annexin IX (ANX IX) has been identified as a 20E-inducible gene in dying ASGs, and we show here that its expression is down-regulated in tissues destined to die but not in tissues that survive pupal metamorphosis. ANX IX expression was high in the ASGs during the feeding period, when the ecdysteroid titer was low, and decreased in response to the rising ecdysteroid titer that triggered pupal metamorphosis. Before gut purge, in vitro exposure of the ASGs to 20E levels corresponding to the ecdysteroid concentration present at the time of gut purge caused a decrease in ANX IX messenger RNA levels. Expression profiles of EcR and USP, and the 20E concentration-responses of these genes, indicate the importance of the relative abundance of EcR-A and EcR-B1 isoforms in ANX IX regulation. These results suggest an involvement of ANX IX in the determination of PCD timing by delaying or suppressing the response to the increase in hemolymph ecdysteroid concentration during the prepupal period.
Keywords: annexin, Bombyx, 20-hydroxyecdysone, EcR, programmed cell death
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.23.533
2. Release of Ecdysteroid-Phosphates from Egg Yolk Granules and Their Dephosphorylation during Early Embryonic Development in Silkworm, Bombyx mori
Ryouichi Yamada, Yumi Yamahama, and Haruyuki Sonobe
Zoological Science Volume 22, Issue 2 (February 2005) pp. 187–198
Abstract
Newly laid eggs of many insect species store maternal ecdysteroids as physiologically inactive phosphoric esters. In the silkworm Bombyx mori, we previously reported the presence of a specific enzyme, called ecdysteroid-phosphate phosphatase (EPPase), which catalyzes the dephosphorylation of ecdysteroid-phosphates to increase the amount of free ecdysteroids during early embryonic development. In this study, we demonstrated that (1) EPPase is found in the cytosol of yolk cells, (2) ecdysteroid-phosphates are localized in yolk granules, being bound to the yolk protein vitellin (Vn), and (3) Vn-bound ecdysteroid-phosphates are scarcely hydrolyzed by EPPase, although free ecdysteroid-phosphates are completely hydrolyzed by EPPase. Thus, we investigated the mechanism by which ecdysteroid-phosphates dissociate from the Vn-ecdysteroid-phosphate complex, and indicated that the acidification of yolk granules causes the dissociation of ecdysteroid-phosphates from the Vn-ecdysteroid-phosphate complex and thereby ecdysteroid-phosphates are released from yolk granules into the cytosol. Indeed, the presence of vacuolar-type proton-translocating ATPase in the membrane fraction of yolk granules was also verified by Western blot analysis. Our experiments revealed that Vn functions as a reservoir of maternal ovarian ecdysteroid-phosphates as well as a nutritional source during embryonic development. This is the first report showing the biochemical mechanism by which maternal Vn-bound ecdysteroid-phosphates function during early embryonic development.
Keywords: ecdysteroids, phosphatase, V-ATPase, vitellin, embryonic development
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.22.187
3. Establishment of a Sandwich ELISA System to Detect Diapause Hormone, and Developmental Profile of Hormone Levels in Egg and Subesophageal Ganglion of the Silkworm, Bombyx mori
Norio Kitagawa, Kunihiro Shiomi, Kunio Imai, Teruyuki Niimi, Toshinobu Yaginuma, and Okitsugu Yamashita
Zoological Science Volume 22, Issue 2 (February 2005) pp. 213–221
Abstract
In the silkworm Bombyx mori, diapause hormone (DH) is produced in the female subesophageal ganglion (SG) and induces embryonic diapause by targeting developing ovaries. DH is processed from a precursor protein consisting of DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides (SGNPs). Because these five neuropeptides share a common sequence, FXPRLamide, at the C-terminus, a direct and specific assay for DH itself is required in order to understand the profile of concentration changes. In this study, we produced a mouse monoclonal antibody (anti-DH[N] mAb) against the N-terminal region of DH and developed a sandwich enzyme-linked immunosorbent assay using the anti-DH[N] mAb and a rabbit polyclonal antibody against the C-terminus of DH. This procedure enabled us to specifically quantify the DH molecule at femtomolar levels (equivalent to 1/10 of SG). We then plotted DH levels in eggs and SGs during embryonic and post-embryonic development. DH was present in late-stage embryos that had been destined for the production of both diapause and nondiapause eggs. DH levels in SG gradually increased in both types during larval development and peaked at the early pupal stage. At the middle pupal stage, DH levels in SG and SG-brain complex decreased markedly in the diapause-egg producing type, thus indicating active release of DH into the hemolymph. From 5th instar larva to adult, no sexual differences in DH levels were observed in SGs or SG-brain complexes from diapause and nondiapause egg-producing types.
Keywords: Diapause hormone, FXPRLamide neuropeptide family, bivoltinism, Bombyx mori, subesophageal ganglion, sandwich enzyme-linked immunosorbent assay
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.22.213
4. Effects of Applaud on the Growth of Silkworm (Lepidoptera: Bombycidae)
Maria E. Vassarmidaki, Paschalis C. Harizanis, and Sergios Katsikis
Journal of Economic Entomology Volume 93, Issue 2 (April 2000) pp. 290–292
Abstract
An experiment was carried out to evaluate the effect of the insecticide Applaud (buprofezin 25% WP) on the silkworm Bombyx mori (L.). This insecticide belongs to the class of insect growth regulators (IGR). The larvae were fed on leaves treated with 3 different concentrations (0.5, 1, 2 g/liter) of Applaud on the 1st d of each instar. Analysis of data with the Tukey–Kramer test at 1% significant level revealed that mortality and larval duration did not differ among the treatments. On the contrary, the larval weight, which was estimated just before mounting (procedure during which the mature larva climbing on a branch or other material to spin the cocoon), differed among the treatments. Also, cocoon weight, shell weight, and cocoon sericin and fibroin content were different among the treatments, except the shell cocoon ratio. Maximum weight was observed in the controls and minimum in the last instar treatments. Our data suggest that supplementation of Applaud through food to larvae does not affect their mortality rate. On the contrary, it affects larval growth and cocoon parameters.
Keywords: Bombyx mori, buprofezin, larval duration, larval weight, cocoon parameters
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1603%2F0022-0493%282000%29093%5B0290%3AEOAOTG%5D2.0.CO%3B2
5. Stress induction of Bm1 RNA in silkworm larvae: SINEs, an unusual class of stress genes
Richard H. Kimura, Prabhakara V. Choudary, Koni K. Stone, and Carl W. Schmid
Cell Stress & Chaperones Volume 6, Issue 3 (July 2001) pp. 263–272
This study surveys the induction of RNA polymerase III (Pol III)–directed expression of short interspersed element (SINE) transcripts by various stresses in an animal model, silkworm larvae. Sublethal heat shock and exposure to several toxic compounds increase the level of Bm1 RNA, the silkworm SINE transcript, while also transiently increasing expression of a well-characterized stress-induced transcript, Hsp70 messenger RNA (mRNA). In certain cases, the Bm1 RNA response coincides with that of Hsp70 mRNA, but more often Bm1 RNA responds later in recovery. Baculovirus infection and exposure to certain toxic compounds increase Bm1 RNA but not Hsp70 mRNA, showing that SINE induction is not necessarily coupled to transcription of this particular heat shock gene. SINEs behave as an additional class of stress-inducible genes in living animals but are unusual as stress genes because of their high copy number, genomic dispersion, and Pol III–directed transcription.
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1379%2F1466-1268%282001%29006%3C0263%3ASIOBRI%3E2.0.CO%3B2
6. The Bmdsx transgene including trimmed introns is sex-specifically spliced in tissues of the silkworm, Bombyx mori
Shunsuke Funaguma, Masataka G. Suzuki, Toshiki Tamura, and Toru Shimada
Journal of Insect Science Volume 5, Issue 17 (May 2005) pp. 1–6
Abstract
Orthologue of the sex-determining gene doublesex (dsx) and known to be sex-specifically expressed in various tissues of the silkworm, Bombyx mori. Its pre-mRNA is sex-specifically spliced and encodes female-specific or male-specific polypeptides. The open reading frame of Bmdsx consists of 5 exons, of which exons 3 and 4 are female-specific and its pre-mRNA was known to undergo default processing to generate the female-type mRNA. Previous reports have shown that the mechanism of splicing of the doublesex gene is different in Drosophila melanogaster and Bombyx mori. However, intron 4 is so long that it is difficult to identify the intronic cis-element(s) required for male-specific splicing of Bmdsx pre-mRNA using Bmdsx minigenes whose introns are shortened in various manners. As a first step toward discovery of the cis-element, the Bmdsx mini gene, which consisted of exon 1 and 5 and internally shortened introns 2 to 4, was constructed, and transgenic silkworms expressing this construct were generated. Bmdsx pre-mRNA transcribed derived from transgene was sex-specifically spliced. This result shows that the mini gene contained the information necessary for the correct regulation of alternative splicing.
Keywords: alternative splicing, Bmdsx, Bombyx mori, piggyback, long intron
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-document&doi=10.1672%2F1536-2442%282005%29005%5B0001%3ATBTITI%5D2.0.CO%3B2
7. ESTABLISHMENT AND CHARACTERIZATION OF A CONTINUOUS CELL LINE FROM PUPAL OVARIES OF JAPANESE OAK SILKWORM ANTHERAEA YAMAMAI GUERIN-MENEVILLE
SHIGEO IMANISHI, HAJIME INOUE, TAKESHI KAWARABATA, KOYU HARA, MASAKO FUNAKOSHI, CHISA YASUNAGA-AOKI, and KAZUHIKO MITSUDA
In Vitro Cellular & Developmental Biology - Animal Volume 39, Issue 1 (January 2003) pp. 1–3
Abstract
Pupal ovaries of the wild oak silkworm Antheraea yamamai Guerin-Meneville were cultured in MGM-448 (Modified Grace Medium-448) medium containing 10% fetal bovine serum. After the primary culture was set up in 1988, a continuous cell line was obtained in 1991, designated as NISES-Anya-0611 (Anya-0611). The population doubling time was 54 hrs. and 19 min. at 96 passages and 88 hrs. and 29 min. at 387 passages. Spindle-shaped and spherical cells coexisted in the cell group. The cell line karyotype line was typical of lepidopteran cell lines, consisting of numerous small chromosomes. The cell line was distinguished from other lepidopteran cell lines by comparing malic enzyme, phosphoglucose isomerase, phosphoglucose mutase, and isocitric dehydrogenase isozyme patterns. The cell line was highly infected to the Antheraea yamamai nuclear polyhedrosis virus (Anya NPV). The luciferase gene of recombinant Bm NPV (BmNPVP6ETL) was able to express in the cell line, too, so that luciferase recombinant products were able to be detected in the cell body and in supernatant. The Anya NPV clone group was isolated on the cell seat using plaque purification.
Keywords: insect, wild silkworm, primary culture, karyotype, isozyme patterns, nuclear polyhedrosis virus
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1290%2F1543-706X%282003%29039%3C0001%3AEACOAC%3E2.0.CO%3B2
8. Effects of Wolbachia in the uzifly, Exorista sorbillans, a parasitoid of the silkworm, Bombyx mori
H.P. Puttaraju and B.M. Prakash
Journal of Insect Science Volume 5, Issue 30 (November 2005) pp. 1–7
Abstract
The uzifly, Exorista sorbillans (Diptera: Tachinidae), a parasitoid of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), harbours Wolbachia (Rickettsia) endosymbionts. Administration of 0.05 mg/ml oxytetracycline to the adult uziflies removed Wolbachia endosymbionts and resulted in different reproductive disorders, such as i) reduction in fecundity of uninfected females, ii) cytoplasmic incompatibility in crosses between infected males and uninfected females, iii) sterility in the crosses between both males and females from uninfected populations, and iv) sex-ratio distortion in uninfected females irrespective of the presence of Wolbachia in males. However, tetracycline treatment did not have much effect on longevity of the uzifly. These results suggest that the interaction of Wolbachia with its uzifly host is one of mutual symbiosis as it controls the reproductive physiology of its hosts.
Keywords: fecundity, cytoplasmic incompatibility, sterility, sex ratio, tetracycline
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-document&doi=10.1673%2F1536-2442%282005%295%5B1%3AEOWITU%5D2.0.CO%3B2
9. Apoptosis and Adhesion of Hemocytes During Molting Stage of Silkworm, Bombyx mori
Toshio Okazaki, Noriyuki Okudaira, Kikuo Iwabuchi, Hajime Fugo, and Tatsuo Nagai
Zoological Science Volume 23, Issue 3 (March 2006) pp. 299–304
Abstract
To clarify the regulatory mechanism of the rapid changes in the hemocyte density in the silkworm, Bombyx mori, during ecdysis, we evaluated the relationship between the hemocyte density and the incidence of apoptosis during this stage. We also evaluated the role of the sugar chains on the adhesion of hemocytes by analyzing the effects on the hemocyte density of the injection of enzymes that cut sugar chains and monosaccharides into the body cavity.
The hemocyte density was increased in the molting stage and spinning, and then decreased after the ecdysis. During spinning, the diameter of the granulocytes markedly increased, in which fatty granules in the cytoplasm increased, becoming foamy. They were identified to be apoptotic hemocytes using the Hoechst staining and the Comet assay. The decrease in the hemocyte density during spinning was mainly caused by the apoptosis of granulocytes. Next, we focused on the fluctuation of hemocyte density during the molting stage. Examination of the changes in the hemocyte density induced by injecting glycoside hydrolases, neuraminidase, sialic acid, or monosaccharides into the body cavity during the fourth molt stage and the third day in fifth instar larva demonstrated that the alteration of hemocyte density was regulated by the attachment and detachment of hemocytes via a selectin ligand, sugar chains. As with the injection of glycoside hydrolase, neuraminidase, sialic acid and fucose raised the hemocyte detachment, and it was assumed that the selectin ligands include the sialyl Lewis x like sugar chains, the same as mammalian lymphocytes.
Keywords: Bombyx mori, hemocyte, apoptosis, adhesion, sialyl Lewis x
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.23.299
10. Immunocytochemical Identification of Neuroactive Substances in the Antennal Lobe of the Male Silkworm Moth Bombyx mori
Masaaki Iwano and Ryohei Kanzaki
Zoological Science Volume 22, Issue 2 (February 2005) pp. 199–211
Abstract
As a first step towards understanding the functional role of neuroactive substances in the first olfactory center of the male silkworm moth Bombyx mori, we carried out an immunocytochemical identification of antennal lobe neurons. Antibodies against γ-aminobutyric acid (GABA), FMRFamide, serotonin, tyramine and histamine were applied to detect their existence in the antennal lobe. In the present immunocytochemical study, we clarified four antenno-cerebral tracts from their origin and projection pathways to the protocerebrum, and revealed the following immunoreactive cellular organization in the antennal lobe. 1) Local interneurons with cell bodies in the lateral cell cluster showed GABA, FMRFamide and tyramine immunoreactivity. 2) Projection neurons passing through the middle antenno-cerebral tract with cell bodies in the lateral cell cluster showed GABA and FMRFamide immunoreactivity. Projection neurons passing through the outer antenno-cerebral tract with cell bodies in the lateral cell cluster showed FMRFamide immunoreactivity. 3) Centrifugal neurons passing through the inner antenno-cerebral tract b with cell bodies located outside the antennal lobe showed serotonin and tyramine immunoreactivity. Our results revealed basic distribution patterns of neuroactive substances in the antennal lobe and indicated that each projection pathway from the antennal lobe to the protocerebrum contains specific combination of neuro-active substances.
Keywords: neuroactive substances, immunocytochemical, antennal lobe, projection pathway, silkworm moth
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.22.199
11. Gene Expression Profiling in the Silkworm, Bombyx mori, During Early Embryonic Development
Sun-Mee Hong, Si-Kab Nho, Nam-Soon Kim, Jin-Sung Lee, and Seok-Woo Kang
Zoological Science Volume 23, Issue 6 (June 2006) pp. 517–528
Abstract
We prepared a cDNA library for a microarray from eggs of the silkworm, Bombyx mori, at the germ-band formation (24 hours after fertilization) stage. Using a microarray constructed with 2,445 ESTs, we screened gene expression profiles during germ-band formation at six specific time points in the early embryonic stages (from the unfertilized egg to the formation of abdominal leg appendages), and determined 241 of these cDNAs to represent genes that were expressed differentially during the germ-band formation stage. These differentially expressed genes grouped into two clusters. In the early and late clusters, 203 and 38 genes were upregulated, respectively. In the upregulated clusters, we isolated several genes that were associated with development and cell communication, including egalitarian, RAD23b, innexin 2, and senescence-associated protein. Northern blot hybridization revealed that the expression patterns of 14 genes had changed in each of the stages. In this study, we assessed changes in the levels of gene expression in relation to the germ-band formation stages in whole Bombyx embryos.
Keywords: silkworm, Bombyx mori, cDNA microarray, embryogenesis, development, cell communication
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.23.517
12. A Rapid Increase in cAMP in Response to 20-Hydroxyecdysone in the Anterior Silk Glands of the Silkworm, Bombyx mori
Mohamed Elmogy, Jun Terashima, Masatoshi Iga, Masafumi Iwami, and Sho Sakurai
Zoological Science Volume 23, Issue 8 (August 2006) pp. 715–719
Abstract
In the anterior silk glands (ASGs) of the silkworm, Bombyx mori, intracellular cAMP increases transiently to a very high level shortly after the hemolymph ecdysteroid peak in the prepupal period. In cultured ASGs obtained on the day of gut-purge, cAMP levels were increased by 20-hydroxy-ecdysone (20E), and this increase was enhanced by an inhibitor of phosphodiesterase, but was not affected by α-amanitin, indicating the 20E action may not be mediated via gene expression. The increase in cAMP occurred within 30 seconds of exposure to a physiological concentration of 20E (1 μM), and also by ponasterone A. Our findings indicate a nongenomic action of ecdysteroids in insects, which may be an additional mechanism by which this steroid hormone induces acute responses in tissues and cells.
Keywords: ecdysone, cAMP, silk gland, programmed cell death, Bombyx mori
* Corresponding author. Phone: +81-76-264-6250; Fax : +81-76-264-6255; E-mail: ssakurai@kenroku.kanazawa-u.ac.jp
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.23.715
13. Brain-Derived Neurotrophic Factor Promotes Neurite Growth and Survival of Antennal Lobe Neurons in Brain from the Silk Moth, Bombyx mori in vitro
Jin Hee Kim, Dong Kyung Sung, Chan Woo Park, Hun Hee Park, Cheolin Park, Soung-Hoo Jeon, Pil Don Kang, O-Yu Kwon, and Bong Hee Lee
Zoological Science Volume 22, Issue 3 (March 2005) pp. 333–342
Abstract
This study was conducted to investigate effects of brain-derived neurotrophic factor on the neurite growth and the survival rate of antennal lobe neurons in vitro, and secretion of brain-derived neurotrophic factor-like neuropeptide from brain into hemolymph in the silk moth, Bombyx mori. In primary culture of antennal lobe neurons with brain-derived neurotrophic factor, it promoted both a neurite extension of putative antennal lobe projection neurons and an outgrowth of branches from principal neurites of putative antennal interneurons with significance (p<0.05). name="cor1">* Corresponding author. Phone: +82-2-3290-3156; Fax: +82-2-3290-3623; E-mail: bhlee@korea.ac.kr
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.22.333

C. Non mulberry sericulture
1. Impact of Pollen Grains from Bt Transgenic Corn on the Growth and Development of Chinese Tussah Silkworm, Antheraea pernyi (Lepidoptera: Saturniidae)
Wendong Li, Kongming Wu, Xiaoqi Wang, Guirong Wang, and Yuyuan Guo
Environmental Entomology Volume 34, Issue 4 (August 2005) pp. 922–928
Abstract
The tussah silkworm, Antheraea pernyi (Lepidoptera: Saturniidae), is an important natural resource for the silk industry and has been cultured using wild host plants for >2,000 yr in China. To clarify whether there is any risk from pollen of Cry1Ab-containing corn varieties on this insect, the frequency of pollen dispersal and deposition of corn pollen near cornfields and impact on the development of tussah silkworm larvae were studied separately in the field and laboratory. The field survey showed that the pollen density was the highest inside the cornfield with a value of 1,000 grains/cm2. The pollen deposition rapidly declined with distance from the edge of the cornfield as expected in most cases. No significant differences were observed in the amounts of pollen deposited on glass slides positioned at different heights from the ground at each distance. In the laboratory bioassays, there were no significant differences in the larval mortality and weight of Chinese tussah silkworm between treatment with pollen grains from a transgenic corn line and a nontransgenic corn control at a density of 1,000 pollen grains/cm2. Also no significant negative impact was found for efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI), and efficiency of approximate digestion of food (AD) at the level of 1,000 pollen grains/cm2. The results of this study suggest that the impact on the Chinese tussah silkworm of Bt corn pollen from the hybrid to be commercialized in China is negligible in the natural environment.
Keywords: pollen grains, Bt transgenic corn, Chinese tussah silkworm, environmental impact
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1603%2F0046-225X%282005%29034%5B0922%3AIOPGFB%5D2.0.CO%3B2

D. Silk
1. Modeling Of The Stress-Strain Behavior Of Egg Sac Silk Of The Spider Araneus Diadematus
Els Van Nimmen, Kris Gellynck, Tom Gheysens, Lieva Van Langenhove, and Johan Mertens
Journal of Arachnology Volume 33, Issue 2 (August 2005) pp. 629–639
Abstract
Spider silk has attracted the attention of many scientists because of its desirable physical properties. Most of this attention has been devoted to dragline silk, a thread that has high tensile strength, high strain and ultra-low weight. To help understand structure-property relationships in spider silks, the tensile behavior of egg sac (cylindrical gland) silk of Araneus diadematus Clerck 1757 was compared with dragline (major ampullate gland) and silkworm silks. In addition, stress-strain curves of egg sac silk were simulated by a spring-dashpot model, specifically a Standard Linear Solid (SLS) model. The SLS model consists of a spring in series with a dashpot and in parallel with another spring, resulting in three unknown parameters. The average stress-strain curve of fibers from five different egg sacs could be accurately described by the model. Closer examination of the individual stress-strain curves revealed that in each egg sac two populations of fibers could be distinguished based on the parameters of the SLS model. The stress-strain curves of the two populations clearly differed in their behavior beyond the yield point and were probably derived from two different layers within the egg sac. This indicates that silks in the two layers of A. diadematus egg sacs probably have different tensile behavior.
Keywords: Spider silk, tensile behavior, cocoon, cylindrical gland, tubuliform gland, Araneidae
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1636%2FCS05-5.1
2. Physical properties of Hydropsyche siltalai (Trichoptera) net silk
Sarah A. BrownA, Graeme D. RuxtonA, and Stuart HumphriesB
Journal of the North American Benthological Society ;Volume 23, Issue 4 (December 2004)
Abstract
Suspension-feeding trichopterans spin a fine-silk capture net that is used to remove suspended matter from the water. The efficiency of these nets has previously been studied by considering the geometry of the web structure but the material from which the nets is constructed has received little attention. We report measurements of the tensile strength and extensibility of net silk from Hydropsyche siltalai. These measurements place caddisfly silk as one of the weakest natural silks so far reported, with a mean tensile strength of 221 ± 22 megaNewtons (MN)/m2. We also show that H. siltalai silk can more than double in length before catastrophic breakage, and that the silk is at least 2 orders of magnitude stronger than the maximum force estimated to act upon it in situ. Possible reasons for this disparity include constraints of evolutionary history and safety margins to prevent net failure or performance reduction.
Keywords: Hydropsyche siltalai, tensile strength, extensibility, breaking strain, stress
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1899%2F0887-3593%282004%29023%3C0771%3APPOHST%3E2.0.CO%3B2
3. Spider Dragline Silk: Correlated And Mosaic Evolution In High-Performance Biological Materials
Brook O. Swanson, Todd A. Blackledge, Adam P. Summers, and Cheryl Y. Hayashi
Evolution Volume 60, Issue 12 (December 2006) pp. 2539–2551
Abstract
The evolution of biological materials is a critical, yet poorly understood, component in the generation of biodiversity. For example, the diversification of spiders is correlated with evolutionary changes in the way they use silk, and the material properties of these fibers, such as strength, toughness, extensibility, and stiffness, have profound effects on ecological function. Here, we examine the evolution of the material properties of dragline silk across a phylogenetically diverse sample of species in the Araneomorphae (true spiders). The silks we studied are generally stronger than other biological materials and tougher than most biological or man-made fibers, but their material properties are highly variable; for example, strength and toughness vary more than fourfold among the 21 species we investigated. Furthermore, associations between different properties are complex. Some traits, such as strength and extensibility, seem to evolve independently and show no evidence of correlation or trade-off across species, even though trade-offs between these properties are observed within species. Material properties retain different levels of phylogenetic signal, suggesting that traits such as extensibility and toughness may be subject to different types or intensities of selection in several spider lineages. The picture that emerges is complex, with a mosaic pattern of trait evolution producing a diverse set of materials across spider species. These results show that the properties of biological materials are the target of selection, and that these changes can produce evolutionarily and ecologically important diversity.
Keywords: Biomaterials, biomechanics, independent contrasts, major ampullate silk, phylogenetic signal, tensile test, web
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1554%2F06-267.1
4. Spider Silk Proteins – Mechanical Property and Gene Sequence
Anna Rising, Helena Nimmervoll, Stefan Grip, Armando Fernandez-Arias, Erica Storckenfeldt, David P Knight, Fritz Vollrath, and Wilhelm Engström
Zoological Science Volume 22, Issue 3 (March 2005) pp. 273–281
Abstract
Spiders spin up to seven different types of silk and each type possesses different mechanical properties. The reports on base sequences of spider silk protein genes have gained importance as the mechanical properties of silk fibers have been revealed. This review aims to link recent molecular data, often translated into amino acid sequences and predicted three dimensional structural motifs, to known mechanical properties.
Keywords: spider silk, MaSp1, MaSp2, structure, function
Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.2108%2Fzsj.22.273
5. The Combing of Cribellar Silk by the Prithine Misionella Mendensis, with Notes on Other Filistatid Spiders (Araneae: Filistatidae)
LARA LOPARDO and MARTÍN J. RAMÍREZ
American Museum Novitates Volume 3563, Issue 1 (May 2007) pp. 1–14
Abstract
We present the first observations of the combing and attaching behavior in the subfamily Prithinae (Filistatidae), taken from Misionella mendensis. We compare its web architecture with that of other prithines (Pritha nana and Pikelinia sp. from Chile) and filistatines (Kukulcania hibernalis and Filistata insidiatrix). The combing behavior of M. mendensis corresponds to the stereotyped type I combing behavior, as is known for other filistatids. However, M. mendensis attaches the cribellar segments in a unique way, splitting the cribellar segment longitudinally and pushing each half to the substrate, attaching the silk with the tarsi of both legs IV simultaneously. These stereotyped movements result in web units of a very characteristic structure. We report the same split attachment behavior in the prithine Pikelinia tambilloi. We scored these observations into a previous dataset for filistatid relationships. Because of the missing observations on attachment behavior in the North American basal genus Filistatinella, the sister group of all other prithines, the evolution of split cribellar strands is a potential synapomorphic characteristic for the Prithinae, or at least the subgroup excluding its basal taxon.Link to full article (you may need subscription): http://www.bioone.org/perlserv/?request=get-pdf&doi=10.1206%2F0003-0082%282007%29529%5B1%3ATCOCSB%5D2.0.CO%3B2

Anthocyanins from mulberry fruits - a challenge for mulberry germplasms

Anthocyanins are edible pigments, which hold potential use as natural food colourants. As the safety of synthetic pigments are doubted and in the wake of increasing demand for natural food colourants their significance in food industry increase. Anthocyanins are reported to yield attractive colours such as orange, red and blue. Since they are water-soluble their incorporation into aqueous food systems is easy. Apart from the colouring property anthocyanins are also known to possess antioxidant property and improve visual acuity. They also possess antineoplastic, radiation –protective, vasotonic, vasoprotective, anti-inflammatory, chemo and hepato - protective properties.
Xueming Liu and his co workers at the Sericultural Research Institute, Guangdong Academy of Agricultural Sciences, China in 2004 developed a cheap and industrially feasible method for purification of anthocyanins from mulberry fruit which could be used as a red food colourant of high colour value (of above 100). They found that out of 31 Chinese mulberry cultivars tested the total anthocyanin yield varied from 147.68 mg. to 2725.46 mg. per litre of fruit juice. Extraction and purification was done by using acidified ethanol as effluent solvent and cross-linked polystyrene copolymer - macro porous resin as adsorbant. The results indicated that total sugars, total acids and vitamins remained intact in the residual juice after removal of anthocyanins and that the residual juice could be fermented in order to produce products such as juice, wine and sauce.
In many parts of the globe mulberry is grown for its fruit. The fruit is known to have many medicinal properties and used for making jam, wine etc. As the genera Morus has been domesticated over thousands of years and constantly been subjected to heterosis breeding (mainly for improving leaf yield), it would not be impossible for evolving breeds suitable for berry production. The finding offers possible industrial use of mulberry as a source of anthocyanins as natural food colourant, which could enhance the overall profitability of sericulture. Anthocyanin content was found to depend on climate and area of cultivation and it was higher on a sunny day. This finding holds promise for tropical sericulture countries for profiting from industrial anthocyanin production from mulberry through better anthocyanin recovery.
This offers a challenging task to the mulberry germplasms resources across the globe, in exploration and collection of fruit yielding mulberry species; their Characterization, cataloguing and evaluation for anthocyanin content by using traditional as well as modern means and bio technology tools; developing an information system about these cultivars or varieties; training and global coordination of utilization of these genetic stocks and finally in evolving suitable breeding strategies to improve the anthocyanin content in potential breeds by collaboration with various research stations in the field of sericulture, plant genetics & breeding, biotechnology and pharmacology.

Reference: Liu, Xueming et. al. (2004): Quantification and purification of Mulberry anthocyanins with macroporous resins.; Journal of Bio medicine and Biotechnology; 2004:5 326-331, http://www.jbb.hindawi.com/.

Franklin on SILK

Benjamin Franklin, one of the most important Founding Fathers of the United States said
“…….It is the happiest of all inventions of clothing…… The wear of silken garments continues so much longer, from the strength of the materials, as to give it greatly the preference …….Mulberry trees may be planted in hedge grows, on walker avenues or for shade near a house, where nothing else is wanted to grow……”

SDS PAGE - What each chemical ingredient does?

The importance of Poly Acrylamide Gel electrophoresis in protein research is un questioned. The composition of the gel is complex and the procedure is more an art than science. Precision is the key word in its making. This article provides information regarding the importance of various ingredients of the PAG

Poly acrylamide gel (PAG) had been known as a potential embedding medium for sectioning tissues as early as 1954. Two independent groups Davis and Raymond employed PAG in electrophoresis in 1959. It possesses several electrophoretically desirable features that made it a versatile medium. Poly acrylamide gel separates protein molecules according to both size and charge. It is a synthetic gel, thermo-stable, transparent, strong, relatively chemically inert, can be prepared with a wide range of average pore sizes, can withstand high voltage gradients, feasible to various staining and destaining procedures and can be digested to extract separated fractions or dried for autoradiography and permanent recording. DISC electrophoresis utilizes gels of different pore sizes. The name DISC was derived from the discontinuities in the electrophoretic matrix and coincidentally from the discoid shape of the separated zones of ions (Anbalagan, 1999). There are two layers of gel namely staking gel or spacer gel and resolving gel or separating gel.
Staking gel or spacer gel: It is a large pore poly acrylamide gel (4%). This gel is prepared with Tris buffer pH 6.8 of about 2 pH units lower than that of electrophoresis buffer. These conditions provide an environment for Kohlrausch reactions, as a result, proteins are concentrated to several fold and a thin starting zone of the order of 19 microns is achieved in a few minutes. This gel is cast over the resolving gel. The height of the staking gel region was always maintained more than double the height and the volume of the sample to be applied.
Resolving gel or Separating Gel: This is a small pore polyacryl amide gel (3 - 30%). The Tris buffer used is of pH 8.8. In this gel, macro molecules separate according to their size. In the present experiment, 8%, 10% and 12% Resolving gel were used for separating different range of proteins. 8% gel for 24 – 205 kD proteins, 10% gel for 14-205 kD proteins and 12% gel for 14-66 kD proteins
The chemical ingredients of the gel are the following
Tris (tris (hydroxy methyl) aminomethane) (C4H11NO3; mw: 121.14). It has been used as a buffer because it is an innocuous substance to most proteins. Its pKa is 8.3 at 20°C and reasonably a very satisfactory buffer in the pH range 7.0 – 9.0.
Glycine (Amino Acetic Acid) (C2H5NO2; mw: 75.07). Glycine has been used as the source of trailing ion or slow ion because its pKa is 9.69 and mobility of glycinate are such that the effective mobility can be set at a value below that of the slowest known proteins of net negative charge in the pH range. The minimum pH of this range is somewhere around 8.0.
Acrylamide (C3H5NO; mw: 71.08). It is a white crystalline powder. While dissolving in water, autopolymerisation of acrylamide takes place. It is a slow spontaneous process by which acrylamide molecules join together by head on tail fashion. But in presence of free radicals generating system, acrylamide monomers are activated into a free-radical state. These activated monomers polymerise quickly and form long chain polymers. This kind of reaction is known as Vinyl addition polymerisation. A solution of these polymer chains becomes viscous but does not form a gel, because the chains simply slide over one another. Gel formation requires hooking various chains together. Acrylamide is a neuro toxin. It is also essential to store acrylamide in a cool dark and dry place to reduce autopolymerisation and hydrolysis.
Bisacrylamide (N,N’-Methylenebisacrylamide) (C7H10N2O2; mw: 154.17). Bisacrylamide is the most frequently used cross linking agent for poly acryl- amide gels. Chemically it is thought of having two-acrylamide molecules coupled head to head at their non-reactive ends. Bisacrylamide was preserved at 4°C.
Sodium Dodecyl Sulphate (SDS) (C12H25NaO4S; mw: 288.38). SDS is the most common dissociating agent used to denature native proteins to individual polypeptides. When a protein mixture is heated to 100°C in presence of SDS, the detergent wraps around the polypeptide backbone. It binds to polypeptides in a constant weight ratio of 1.4 g/g of polypeptide. In this process, the intrinsic charges of polypeptides becomes negligible when compared to the negative charges contributed by SDS. Thus polypeptides after treatment becomes a rod like structure possessing a uniform charge density, that is same net negative charge per unit length. Mobilities of these proteins will be a linear function of the logarithms of their molecular weights.
Ammonium per sulphate (APS) (N2H8S2O8; mw: 228.2). APS is an initiator for gel formation. APS was stored at 4°C.
TEMED (N, N, N’, N’-tetramethylethylenediamine) (C6H16N2; mw: 116.21). Chemical polymerisation of acrylamide gel is used for SDS-PAGE. It can be initiated by ammonium per sulphate and the quarternary amine, N, N, N’, N’-tetramethylethylenediamine (TEMED). The rate of polymerisation and the properties of the resulting gel depends on the concentration of APS and TEMED. Increasing the amount of APS and TEMED results in a decrease in the average polymer chain length, an increase in gel turbidity and a decrease in gel elasticity. Decreasing the amount of initiators shows the reverse effect. It is recommended that lowest catalysts concentrations that will allow polymerisation in the optimal period of time should be used. APS and TEMED are used, approximately in equimoloar concentrations in the range of 1 to 10 mM. TEMED was stored at 4°C.
The following chemicals are used for processing of the gel and the protein samples visualized in it.
Bromo Phenol Blue (BPB) (3’, 3’’, 5’, 5’’-Tetrabromophenolsulph- onephthalein) (C19H10Br4O5S; mw: 669.99). BPB is the universal marker dye. Proteins and nucleic acids are mostly colourless. When they are subjected to electrophoresis, it is important to stop the run before they run off the gel. BPB is the most commonly employed tracking dye, because it is viable in alkali and neutral pH, it is a small molecule, it is ionisable and it is negatively charged above pH 4.6 and hence moves towards anode. Being a small molecule it moves ahead of most proteins and nucleic acids. As it reaches the anodic end of the electrophoresis medium electrophoresis is stopped. It can bind with proteins weakly and give blue colour.
Glycerol (C3H8O3; mw: 92.09). It is a preservative and a weighing agent. Additon of glycerol (20-30 or 50%) is often recommended for the storage of enzymes. Glycerol maintains the protein solution at very low temperature, without freezing. It also helps to weigh down the sample into the wells without being spread while loading.
Coomassie Brilliant Blue (CBB) (C45H44N3NaO7S2; mw: 825.97). CBB is the most popular protein stain. It is an anionic dye, which binds with proteins non-specifically. The structure of CBB is predominantly non-polar. So is usually used (0.025%) in methanolic solution (40%) and Acetic Acid (7%). Proteins in the gel are fixed by acetic acid and simultaneously stained. The excess dye incorporated in the gel can be removed by destaining with the same solution containing no dye. The proteins are detected as blue bands on a clear background. As SDS is also anionic in nature, it is reported to interfere with staining process. Therefore, large volume of staining solution is recommended. Approximately 10 times the volume of the gel.
Butanol (C4H10O; mw: 74.12). Water saturated butanol is used as an overlay solution on the resolving gel.
Beta Mercapto Ethanol (HS-CH2CH2OH; mw: 78.13). BME was procured from LKB, Bromma, Sweden and was stored at 4°C.
References

1. Anbalagan K (1999). An Introduction to Electrophoresis. Ed. Anbalagan K. pub. The electrophoresis institute, Biotech-Yercaud, Salem, India.
2. Sambrook J and Russel DW (2001). Molecular Cloning: A Laboratory Manual. Cold Spring Harbour, New York.

SILK dumping- the theory and practice. Is the contingent protection substantiated?

The recent imposition of anti dumping duties on Chinese silk imports to India has stirred up the global silk scenario. The issue whether there is dumping of specific grade raw silks by China is debated with in and out side the countries concerned. This article takes a glimpse at the economic theory behind dumping and anti dumping strategies, as the bulk of the current debates is found to be deficient in the theory behind the phenomenon. The discussion is published in two parts.

Part-1

Dumping is usually understood to mean that a product is exported at a price lower than the price at which the identical or a similar product is sold by the same producers on the exporting country’s domestic market. Dumping can be either a result of monopoly or an instrument to create or strengthen monopoly.
The conditions mandatory for dumping to take place are
1. Presence of an imperfect market where price discrimination between markets is possible. (Because in imperfect markets firms are price setters not price takers) 2. Segmented markets where there is no arbitrage easily possible between markets.
Only if these two conditions are satisfied is it possible for the exporting firm to engage in dumping. For any firm, price discrimination in favor of exports is more common because the share of exports is usually lesser than the domestic demand.
The classic view at dumping identifies the following types
· Private long term dumping and price discrimination
· Subsidized and public dumping
· Dumping in the interest of the exporting country
· Short term dumping
Private long term dumping and price discrimination
Private long-term dumping and price discrimination can result from the profit maximizing policies of a discriminating monopolist. The behavior of the monopolist will be based on the elasticity of demand existing in the domestic and foreign markets. Suppose the domestic demand is less elastic compared to the foreign demand he will restrict the supply of goods in the domestic market (to raise the prices) and dump the product in the foreign market to take advantage of the price elasticity of demand existing there. This concept can be graphically represented.

figure:1


In the figure 1; Dh D’h and Df D’f represent the domestic and foreign demand curves respectively. Mh M’h and Mf M’f represent marginal domestic and marginal foreign revenue curves. The horizontal summing of the two marginal revenue curves gives the aggregate marginal revenue curve Ma M’a. The domestic producers marginal cost curve is C C’. The discriminating monopolist will produce at the point where his aggregate marginal revenue is equal to his marginal cost. Total output will be OR, sales at home- O Wh, and sales abroad- O Wf. The producer has equated his marginal revenue in both markets to his marginal cost, hence satisfying the condition for his private optimum. The price at home is O Ph and price of export is O Pf. In the diagram it is assumed that at the relevant points the elasticity of demand at home is lower than that abroad, so that the domestic price is higher, and thus there is dumping. The essence of private dumping is price discrimination.
Subsidized and public dumping
This is a case of competitive market, not monopoly. The case of an export subsidy is represented in figure 2. The domestic supply curve, which is equal to marginal costs is represented by Sh S’h. Domestic demand curve is Dh D’h. Here price is equal to marginal cost of production. The foreign demand is assumed to be perfectly elastic as represented by the foreign demand curve Df D’f. An export subsidy of Df S is installed which raises the domestic price to OS. Consumption falls and production rises. For the higher domestic price to be possible there have to be either transport costs or a domestic tariff. Domestic consumers pay the price OS and foreign consumers pay a lower O Df. Thus there is dumping.

figure:2
The case of public dumping is more or less the same. Here we are concerned with export marketing arrangements in which there are private competitive producers and a marketing board intervenes to protect exports, rather than maximizing the profit of producers. The board will charge a higher price to the domestic consumer and the profit margin will be used to provide export subsidy.
Dumping in the interest of the exporting country
As distinct from the private interest of the monopolist, dumping can also be in the national interest of the exporting country. National policy in the form of tariffs can make private long term dumping possible. If the foreign demand curve is perfectly elastic then a price equal to the marginal cost can be put for both the domestic and foreign markets. If the foreign demand curve is downward sloping the national optimum demands that in the export market marginal cost to be made equal to marginal revenue and in the domestic market marginal cost to be made equal to average revenue. Thus export price exceeds the domestic price (reverse dumping). In this situation by imposing an optimum export tax the country forces the exporters to bring down the export prices which in effect can lead to dumping.
Short term dumping
Short term dumping is of two types namely sporadic and predatory. Sporadic dumping is the fall in foreign supply prices due to variations in production abroad due to various technical reasons etc. Though a fall in prices is always beneficial to the consumers, it increases the risk of domestic producers.
Predatory dumping is not just a manifestation of monopoly but a technique to maintain it. A foreign dominant supplier may temporarily reduce his supply price so as to force out a domestic producer trying to enter or extent his share of the market, the foreign supplier being able to sustain a price war longer than the domestic supplier. Predatory dumping is effective only if the foreign exporter is able to sustain a monopoly. It is not sufficient for him that he is able to force out a domestic supplier. If he has to compete with other foreign suppliers he may not subsequently be able to raise his price.
Anti Dumping - Meaning and concept
Anti dumping is a measure to rectify the situation arising out of the dumping of goods and its trade distortive effect. Thus the purpose of anti dumping duty is to re establish fair trade. Many countries have anti dumping regulation of some kind. One outcome of the Kennedy round of GATT negotiations was an agreement establishing an international anti dumping code which now governs the anti dumping policies of signatory countries. Dumping refers to private dumping and is considered to occur “if the export price of the product exported from one country to other is less than the comparable price for the like product when destined for consumption on the exporting country. Action could be taken if there is material injury to the domestic producers and sufficient evidence of the injury. Countervailing duties can be imposed to offset subsidies.
The important concern is with short term dumping, which creates uncertainty and may be an instrument of monopoly. The concern is often with producer rather than the consumer interests. If the import price falls there will be domestic income re distribution effect, which should be prevented. Another concern is that of fairness. Dumping seems unfair when it is believed that the export price is below the foreign suppliers average cost of production.
Anti dumping duty and customs duty.
Customs duties fall in the realm of trade and fiscal policies of the Government while anti dumping and anti subsidy measures are there as trade remedial measures. The object of anti dumping and allied duties is to offset the injurious effects of international price discrimination while customs duties have implication for the government revenue and for overall development of the economy. Anti dumping duties are not necessarily in the nature of a tax measure in as much as the authority is empowered to suspend these duties in case of an exporter offering a price undertaking. Thus such measures are not always in the form of duties/ tax. Anti dumping and anti subsidy duties are levied against exporter/ country in as much as they are country specific and exporter specific as against the customs duties which are general and universally applicable to all imports irrespective of the country of origin and the exporter.
Anti dumping (AD) and countervailing (CV) procedures- implications for developing countries
Contrary to their design as temporary means to offset unfair competition, these trade defense measures are in practice used as a long term strategy for various economic difficulties. Used (abused) as a substitute for positive adjustment measures ad and CV actions are also utilized to deal with structural problems. Applied as an instrument for tackling the negative consequences of trade liberalization they became a common tool to protect domestic producers from foreign competition. Faced with the need to protect sensitive domestic industries from increased imports or price slumps, countries often decide to use AD/ CV measures instead of (the more costly) safeguard measures provided for in the GATT 1994.
The WTO era saw a notable rise in AD and CV proceedings. Anti dumping investigations more than doubled and countervailing investigations increased six fold. Countries that appreciated their exchange rate regimes also seem to have used anti dumping to limit current account deficits caused by external shocks.
The almost exclusive restriction of AD initiations to the Big four (Australia, Canada, European Union and United States) was replaced by a broadened field of applicants. Argentina, Brazil, India, Mexico and South Africa became active users, responsible for a significant number of new investigations. Together they account for about one quarter of the AD investigations initiated since 1995. The United States and the European Union initiated two thirds of all CV investigations. Altogether developed countries were behind more than 80% of the overall number for CV investigations initiated in the WTO period.
Anti dumping and countervailing actions has a variety of negative implications.
· They can create substantial distortions with damaging effects on trade and competition.
· The imposition (or even the mere threat) of a duty may lead exporting firms to change production and seek alternative sources of supply.
· The exclusive focus on certain domestic producer neglects costs imposed on consumers due to price increases.
· The existence of these trade defense measures encourages rent seeking behavior by import competing firms.

To be continued.........

Exclusive interview with Dr. Panomir Tzenov, Executive Director of Bulgarian National Center of Agricultural Sciences (NCAS)

Dr. PANOMIR IVANOV TZENOV was born in Vratza, Bulgaria in 1961. He took his MSc from The University of Zootechnics and Veterinary Medicine – Stara Zagora in Animal breeding engineering – sericulture. He obtained his PhD. in sericulture in 1996.
Dr. Tzenov started his career as a technologist in silkworm egg production at the “Silkworm breeding and egg production enterprise”, Vratza, under the Sericulture Experiment Station (SES) Vratza. He became the head of the station in 1987. From 1994 to 2003 he served as The Director of SES, Vratza and as National Director of the project “Rehabilitation of sericulture”, financed by FAO during 2000 – 2002. Presently he holds the position of Executive director of Bulgarian National Center of Agricultural Sciences (NCAS), Sofia.
He is member of various reputed national and international forums such as International Working Group on Sericulture Germplasm” under FAO, International Working group on the global silk handcraft cottage industries and silk enterprises development” under FAO, The Publishing council at the National Center of Agricultural Sciences, Bulgaria etc. He is the founder president of Black, Caspian Seas and Central Asia Silk Association (BACSA).
He has contributed immensely to general sericulture, silkworm breeding, egg production, rearing technology and cocoon and silk processing. He has 164 published papers to his credit and holds author’s certificates for two commercial silkworm hybrids.
Dr. Tzenov is widely traveled and has participated in more than 30 scientific conferences across Asia and Europe.

Inspite of his busy schedule he has found time to give an exclusive interview to 'The Silkworm' for which The Silkworm is thankful.

Tell me about BACSA, its objectives, membership, mode of operation etc.
The Black, Caspian Seas and Central Asia Silk Association (BACSA) was established after the “International Workshop on Revival and Promotion of Sericultural Industries and Small Enterprise Development in the Black, Caspian Seas and Central Asia Region”, organized by FAO in cooperation with the Government of Uzbekistan and held at Tashkent, Uzbekistan from 11 to 15 April 2005 in order to promote sericulture production in the region countries. The association’s main tasks are to: Generate sericulture projects from external resources, including bilateral and multilateral cooperation; Sensitize respective governments and prospective donors; Promote local and regional joint efforts which allow the cooperation between the countries of the Black, Caspian seas region and Central Asia to develop concrete actions that fortify the sustainable development of the sericulture in the region; Promote making agreements for international scientific-technical cooperation and business relations between the countries involved and Promote market studies, training, and dispersion of sericultural germplasm, and silkworm eggs.

For the operation of the association there are, chosen democratically by the members a President, two Vice-presidents, national coordinators for each member country, members of an Executive Committee. The members of the Executive Committee are directly the people in charge of coordination of all the raised activities for their country, within the regional context. The Executive Committee it is the bridge between the country, the national coordinator and the other countries of the association, to execute the actions defined in the region.

The Committee gathers at least once a year and has the following functions: to evaluate the work made by each national coordinator in activities of coordination in her/his country with respect to the BACASA, to recommend the names of the people in the association to receive training abroad. to evaluate and to watch the handling of the "Rotary Funds" and "Research Funds" that will be probably created and to give the recommendations on orientation and better use of these resources, to present/display the research proposals that require financing on the part of the "Research Fund", to approve the necessary resources for this aim and to give recommendations and suggestions on all publications and written material that takes place within the frame of the BACASA and to advise to the association’s President on the advances and progresses that must take place in the development of the activities and give recommendations her/him on the modifications and corrections that are due to make for the final succes of the projects.
Is sericulture a dying enterprise? Does it have a future?
The status of sericulture depends on many factors. In some countries it is really a dying enterprise, due mainly to their high economical development, combined with lack of any governmental support. On the other hand the selling of raw silk/silk allied products by the Chinese at too low prices during the period 1995 – 2005 led to a collapse of the sericulture industry in many countries. The Chinese sold 1 kg of raw silk for US$ 16-18/kg, 3 A quality. That means the fresh cocoon purchasing price should be about US$ 0. 50 – 0.80. Very few countries have so poor farmers who are ready to produce cocoons at this price. On the other hand in many countries the sericulture farmers are supported by the government. In the last year the raw silk price in China jumped to about US$ 43/kg. Therefore the increasing price of the raw silk at the international market, combined with stable state policy to support the sericulture development are the two key factors for the bright future of sericulture. The availability of local silk market is also very important.
Silkworm rearing within the European union countries is considered as one of the protected and promoted activities, being subsidized by Euro 133 per box of 20.000 eggs. This subsidy creates a considerably high income to the farmer, since it approximately duplicates his total income, added to the cocoon value. The replacement of traditional crops by perennial mulberry cultivation is additionally subsidized by the EU by means of the initial installation cost and the income loss for twenty years.
Considering the above I can make the final conclusion that the sericultural industry has a good future.
What is the relevance of sericulture as an agro industry in the developing and underdeveloped countries?
Apart from giving a high-value product, sericulture is a highly women/old people- focused, labour intensive, rural based, income leveler. From one hectare of irrigated mulberry, from the stage of mulberry cultivation to the stage of weaving and marketing, about twelve persons get employment throughout the year. Since the producers of silk cocoons are mostly small farmers while the costly silk final products can be purchased only by the affluent, it transfers income from the rich to the poor, from the urban to rural families. Internationally also, the silk producing countries are mainly the developing countries while silk products have a high demand in the EU countries, Japan and the USA.
Sericulture is also a drought-proffer because, the mulberry plant whose roots go deep in the soil, does not die during prolonged drought and its leaves will sprout whenever there is rain. In the tropical countries, even with 40% rainfall, there will be two crops of mulberry instead of the normal four or five which means, even in the worst drought year, there will be 40% of normal income for the sericulture families. In some temperate /subtropical countries where the summer is very dry and autumn rearing is impossible without irrigation, is possible to get at least one spring cocoon crop without any irrigation of mulberry.
Sericulture thus scores on every point: One of the highest income from one unit of land; Use of less water and drought resistance; Income leveler - transfer of income from rich to the poor nationally and internationally; Generating high rural employment; Gender benign in favor of women-employment; Silkworm rearing is indoors and has no arduous work-drudgery; A natural fibre and ecologically harmless; Hygroscopic, absorbs body moisture and therefore comfortable to wear; No synthetic substitute and highly demanded in EU countries and the USA; No competitor to food crops.
However, in new areas initial promotion and investment is needed in the establishment stage. This is because, while mulberry can be grown without much difficulty, the art and science of silkworm rearing, marketing arrangements for cocoons, reeling and weaving have to be organized in the initial stages till the industry takes root.
The reeled silk yarn is not perishable and being a low-volume, high-value product it has a ready market and can be transported easily. In fact across countries it is air-freighted and not sent by surface transport as transport cost is a small fraction of the total cost. The more difficult task is the teaching of rearing and organizing of reeling to create a market for cocoons produced by the farmer. Once these two aspects are taken care of, sericulture will entrench itself and will develop. Silk being a natural fiber and hygroscopic, it is comfortable to wear in all seasons as it absorbs body moisture. Sericulture thus fits neatly into the economy of any developing country with a significant rural sector, for quite a few decades to come.
Silkworm has long been identified as a laboratory tool (courtesy Dr. Tazima) but yet to be exploited as one. Why is it so?
Recently the silkworm was used as a laboratory tool for the medicine purposes.
The silkworm genome project is underway. What are its implications to the scientific field and agricultural (sericulture) field?
Scientific field: getting new scientific information about the animal genome.
Agricultural field: creation of new silkworm breeds and hybrids combining precious characters, for example sturdiness with high productivity.
While considering the long history of domestication, the bulk of breeding experiments done, viability to genetic manipulation, genomic information, versatility of sericigenous fauna etc., do you think paucity of competent researchers has been the worst handicap for the sector? What are your suggestions for a remedy?
I do not think that paucity of competent researchers has been the worst handicap for the sector. There are many other reasons, the main ones – insufficient financing, considering the sericulture as a minor sector etc.

Dr. Panomir Tzenov can be contacted at panomir@yahoo.com. For more information on BACSA visit http://www.bacsa-silk.org/index.php?lang=bu

Good news for silk

The provisional production figures released by the Central Silk Board (CSB) revealed that domestic raw silk production is showing an upswing with a record of 18760 tons of raw silk during fiscal 2007. The upward move represents 8.41 percent surge over the previous year figures of 17305 tons; however, the record production was much more than the peak production of 17351 tons achieved in 2001-02. During 2002-03 and 2003-04, the drought conditions in the southern region had deterring effect in silk production as farmers went to the extent of even uprooting the mulberry plantations; whereas the ill effects of the severe drought appear to thin out as mulberry silk production had gathered momentum for the fourth successive year.
Last year, the mulberry silk production, including that of bi-voltine silk was 16805 tons up from 15445 tons from the previous year. The redeeming factor of last year's production however was the signs of superior bi-voltine silk galloping in growth by 12.77 percent to cross the 1000 ton mark.
However, the increase in production only proves that bi-voltine silk had come to stay and was finding increased acceptance at farmer's level every year. For more related news visit http://www.bharattextile.com/newsitems

Uzi egg on larval body!