Analysis of bulked segregants to identify molecular markers linked with cocoon weight and cocoon shell weight in the silkworm Bombyx mori L

Two silkworm strains viz, B20 A (high cocoon shell ratio) and C.Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygosis. Both bulked segregant analysis(BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers closely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number sequence and used for identification of Restriction Fragment Length Polymorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk segregant analysis, DNA from the parents (B20 A, C.Nichi), F1 and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, F1, F2 and their bulks, 10 probes were found to be closely linked to cocoon shell characters.     

Study on<Emphasis Type="Italic">Bombyx mori</Emphasis> silk treated by oxygen plasma

Study of the morphology, aggregation structure and properties ofBombyx mori silk treated by low temperature oxygen plasma showed that slight flutes appeared on the surface ofBombyx mori silk fiber and that its surface structure changed after plasma treatment. The conformation also changed and crystalline degree decreased. The stannic filling rate of treated fiber was improved. Because of etching, the weight of the fiber decreased but the breaking strength changed little after short-time treatment. Project (No. 50073013) supported by the National Natural Science Foundation of China     

Effect of vertebrate hormones and prostaglandins on growth, silk quality and metabolic activities of Bombyx mori L

The economic importance of silkworm has moved biologists to explore various intricate mechanisms of the action of vertebrate hormones. The dietary administration of several vertebrate hormones and prostaglandins enhanced both developmental and metabolic processes of silkworm, Bombyx mori L. The main objective of sericulture research is to apply the results to achieve superior quality silk and greater output, to apply lab findings to achieve desirable ecenomic results.     

家蚕染色体的研究进展

家蚕染色体的研究是家蚕细胞生物学及细胞遗传学的基础工作,由于其染色体的特殊性,过去研究进展较为缓慢。但近年来,取得一定进展,本文就研究家蚕染色体的材料和染色体显带方面的进展进行概述。     

Targeting of human aFGF gene into silkworm,Bombyx mori L. through homologous recombination

INTRODUCTION Transgenic technology developed over the 20years, has become a common tool widely applied tolivestock species because it is technically quitesimple, requiring only the injection of ‘naked’DNA into the nucleus of a fertilized eggs (Hammeret al., 1985; Suraokar and Bradley, 2000). Howeverthis technique has limitations in that the injectedDNA integrates randomly into the genome and thuscould not be expressed in the desired tissue or at theappropriate level. More impor…     

Study on Bombyx mori silk treated by oxygen plasma

INTRODUCTION B. mori silk produced by cultivated silkwormis a textile fiber highly appreciated for its out-standing properties (handle, luster, comfort). Inrecent years there has been an increasing interest inexploiting low-temperature plasma treatment (LTP)of textile fibers. Low-temperature plasma treatment is an en-vironmental friendly technique for modifying thefibers surface to improve surface wettability(Molina et al., 2003), shrink resistance (Jin and Dai,2002), interf…     

Immobilization of foreign protein into polyhedra of Bombyx mori nucleopolyhedrovirus (BmNPV)

In the late phase of Bombyx mori nucleopolyhedrovirus (BmNPV) infection, a large amount of polyhedra appear in the infected cell nucleolus, these polyhedra being dense protein crystals protecting the incorporated virions from the harsh environment. To investigate whether the foreign protein could be immobilized into the polyhedra of BmNPV, two recombinant baculoviruses were generated by a novel BmNPV polyhedrin-plus (polh⁺) Bac-to-Bac system, designated as vBmBac(polh⁺)-enhanced green fluorescent protein (EGFP) and vBmBac(polh⁺)-LacZ, which can express the polyhedrin and foreign protein simultaneously. Light microscopy analysis showed that all viruses produced polyhedra of normal appearance. Green fluorescence can be apparently detected on the surface of the vBmBac(polh⁺)-EGFP polyhedra, but not the BmNPV polyhedra. Fluorescence analysis and anti-desiccation testing confirmed that EGFP was embedded in the polyhedra. As expected, the vBmBac(polh⁺)-LacZ polyhedra contained an amount of LacZ and had a higher β-galactosidase activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting were also performed to verify if the foreign proteins were immobilized into polyhedra. This study provides a new inspiration for efficient preservation of useful proteins and development of new pesticides with toxic proteins.     

Accumulation of 1-deoxynojirimycin in silkworm, <Emphasis Type="Italic">Bombyx mori</Emphasis> L.

1-deoxynojirimycin (1-DNJ) contents in the silkworm,Bombyx mori,at different developmental stages and tissues were investigated by using reverse-phase high-performance liquid chromatography. The 1-DNJ contents of silkworm larvae change significantly with their developmental stages. The male larvae showed higher accumulation efficiency of 1-DNJ than the females and also a significant variation was observed among the silkworm strains. The present results show that tissue distribution of 1-DNJ was significantl...     

人工饲料pH值和缓冲性能对家蚕（Bombyx mori）生长发育的影响

由控制饲料的ｐＨ值和缓冲液浓度来确定饲料的缓冲力，并配制不同水平的人工饲料饲育家蚕，检测三者间对饲料质量影响的主次．结果表明：饲料的缓冲力、ｐＨ值以及缓冲液浓度对家蚕的生长发育有显著影响．饲料缓冲液浓度和缓冲力的增加，饲料ｐＨ值的降低，都会引起蚕体重增量、相对生长率和净生长效率的降低，龄期经过的延长、消化后用于能量代谢的食物量的增加．在检验的ｐＨ值范围内（４．０～５．５），饲料ｐＨ值对家蚕生长发育和适口性的影响要小于饲料缓冲力，而略大于缓冲液浓度．     

家蚕丝胶蛋白基因1(ser-1)启动子的克隆及其活性分析

家蚕ser-1基因是中部丝腺中特异表达组织特异性基因。为研究家蚕ser-1基因在时空上的调控机制,用PCR的方法克隆了家蚕ser-1基因启动子并进行序列分析,进一步构建了由ser-1基因启动子驱动报告基因DsRed的新型表达质粒pSK-ser-DsRed-PolyA,并通过蚕体和家蚕BmN细胞进行了瞬时表达。结果显示,家蚕ser-1基因启动子的TATA框的保守序列为TATAAAA,位于-24～-30处,CAAT框位于-112～-115处;ser-1基因启动子可以驱动红色荧光基因DsRed在家蚕幼虫的中部丝腺组织和培养的BmN细胞中瞬时表达。