Relationship between Biological Characteristics of Beauveria bassiana (Bals.) Vuill and Pathogenicity to Bombyx mori L.

[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.

家蚕Bombyx mori L.染色体的G带组型研究

以今井的涂片法制备染色体标本,采用GUG法进行G-带分染,研究了家蚕早双线期染色体的组型。依照染色体相对长度及带型鉴别了家蚕28对染色体,并绘制了染色体组型模式图。利用限性普斑系统W 染色体上的易位片断作标识,观察到不对称配对二价体,推论此异形二价体即性染色体。性染色体在14—16染色体范围内。

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

The long-arm and short-arm genes of fibroin light chain (L-chain) of silkworm, Bombyx Mori L., and the gene of human acidic fibroblast growth factor were cloned respectively and subsequently inserted into a transfer vector pVL 1392 used as a tool to target the L-chain region of the silkworm genome. Genomic DNA from their offsprings was extracted and the expected targeting was detected using polymerase chain reaction and DNA sequencing, as well as protein analysis. The results showed that positive events occurred and that the FGF gene was integrated into the L-chain locus through homologous recombination.

Molecular Systematic Studies on Chinese Mandarina Silkworm (Bombyx mandarina M.) and Domestic Silkworm (Bombyx mori L.)

Molecular systematic studies on mandarina silkworm (Bombyx mandarina M.) in 11 regions in China and 25 representative strains of domestic silkworm (Bombyx mori L.) were conducted using molecular biology techniques. Results obtained from the analysis of DNA polymorphism and clustering of all the silkworm samples provide new evidence for the view that the domestic silkworm originated from the Chinese mandarina silkworm. On the basis of literature reviewing, a new hypothesis on the origin of the domestic silkworm was put forward. It was thought that the domestic silkworm was most probably domesticated from the Chinese mandarina silkworm of different ecotypes including monovoltinism, bivoltinism and multivoltinism; and that the domestic silkworm had the genetic background of monovoltinism, bivoltinism and multivoltinism at the very beginning of the domestication. The current strains of the domestic silkworm of different voltinism are the evolutionary results of thousands of years of rearing and artificial selections.

关于桑蚕(Bombyx mori L.)对人工饮料摄食性的研究──Ⅰ.不同收蚁时间和饲料含水率对小蚕发育的影响

为解决发育不齐的问题，就家蚕不同收蚁时间、不同饲料含水率对家蚕幼虫发育的影响进行了研究。结果发现：①发育整齐度，孵化当天收蚁＞二夜包＞三夜包＞四夜包；②饲料含水率以73％左右为适当．过高或过低都会延缓蚕的发育，影响发育整齐度。

桑蚕(Bombyx mori L.)1～2龄人工饲料1回育3～5龄桑叶育及其成本分析

通过春、夏２期桑蚕１～２龄人工饲料１回育３～５龄桑叶育的农村试养，结果表明，试验区的茧丝质成绩春季基本接近全龄桑叶育，夏季优于全龄桑叶育；通过小蚕人工饲料育的成本分析，采用１～２龄人工饲料１回育每盒蚕种可节省７．５３元。

辛基酚对家蚕(Bombyx mori L.)生长发育的影响

为探讨辛基酚对鳞翅目模式昆虫家蚕生长发育的影响,使用添加0.01~0.08 g·kg-1辛基酚(4-tert-octylphenol,4-t-OP)的人工饲料饲养家蚕(Bombyx mori L.),研究了4-t-OP对家蚕幼虫和蛹的生长发育速度、生长量、发育整齐度和生命力等影响。结果表明:连续取食0.01 g·kg-1以上浓度4-t-OP的饲料,家蚕幼虫和蛹的生长发育速度(幼虫期和蛹期发育经过时间)、生长量(幼虫期体质量和蛹期茧层量)、生命力(3龄起蚕绝食生命时数、4龄起蚕结茧率、蚕茧的死笼率和羽化率)等都明显下降,抑制眠蚕体质量。4-t-OP对家蚕幼虫生长发育后期、化蛹及羽化等发育变态期的影响更加明显,其在家蚕体内可能有累积效应。添食0.08 g·kg-14-t-OP的家蚕不能完成生活史。研究表明,4-t-OP对家蚕生长发育毒性影响有显著的浓度效应和时间效应。

Prevalence of Muscardine Disease in Different Silkworm Hybrid, Bombyx Mori L. under Agro-climatic Conditions in Aurangabad （M.S.）, India

A study was carried out in Dr. Babasaheb Ambedkar Marathwada University Campus Aurangabad, Maharashtra State, India for analyzing the prevalence of Muscardine disease during rainy, winter and summer season in bivoltine x bivoltine hybrids viz. CSR2 × CSR4, CSR4 × CSR2 and multi × bivoltine hybrid PM × CSR2. Observation on Muscardine disease was recorded till the onset of spinning. Analysis of results shows that disease prevalence was more in bivoltine x bivoltine hybrids compare to multi × bivoltine hybrids. PM × CSR2 was found to be more resistant towards Muscardine disease compared to other hybrids under agro-climatic conditions of Aurangabad.

Screening and Cloning of RAPD Marker of Fluoride Tolerance Gene in Silkworm,Bombyx mori

In this study,silkworm strain T6,tolerant to fluoride,and silkworm strain 733xin,highly sensitive to fluoride,were used to construct the near-isogenic lines.300 random primers were used in RAPD amplification to DNAs of these lines.A molecular marker named S207 was found linked to the fluoride tolerance gene.Examination to F 2 segregated individuals of the above lines verified that this molecular marker was reliable.Subsequently,the molecular marker was cloned into a T vector (pUCm-T) for sequencing.Comparing with sequences available in the GenBank showed that this molecular marker was novel.We plan to convert it into a SCAR marker to facilitate establishment of a molecular marker assisted breeding system.

Study on Key Technique of Artificial Insemination for Silkworm,Bombyx mori

[Objective] The aim of this study was to investigate the efficient technique of artificial insemination for silkworm. [Method] Sperms were extracted from bursa copulatrix of female moths mated for 30 min through extruding and centrifugal method, and then the semen was injected into other virgin moths with trypsinase. [ Result] A high-effective collection technology of spermatids from silkworm was established successfully, 50 μl semen could be collected by only one person in each hour. The survival rate of spermatids was over 80% in vito after collected from bursa copulatrix, while the obtained semen was quite pure and the average fertilization rate of silkworm was 76,5%. [ Conclusion] The establishment of high-effective semen extraction technique of silkworm provides the technical basis for studies on other related techniques for silkworm sperm.

关于桑蚕(Bombyx moriL.)对人工饲料摄食性的研究 Ⅱ.饲料的简易化制作和同一蚕品种对人工饲料摄食性的个体差异

为解决人工饲料育蚕发育不齐问题 ,就饲料的不同调制方法对桑蚕幼虫发育的影响以及同一蚕品种个体间的差异进行了研究 .结果发现 :1)在饲料制作上必须进行蒸煮灭菌 ,微波炉加热灭菌与蒸煮的效果相近 ,不经加热杀菌简易化制作的效果都不理想 ;2 )同一蚕品种个体间对人工饲料的摄食性存在差异 .对桑叶粉及蔗糖等摄食促进物质的感受性 ,高食性蚕比低食性蚕敏感 ;而对豆粕粉中摄食阻碍物质的感受性 ,低食性蚕比高食性蚕敏感 .研究认为 ,要提高人工饲料育蚕的群体摄食性和发育整齐度 。

Development and Utilization of Naturally Colored Cocoon Resources of Bombyx mori

This paper summarized the diversity and prominent characteristics of naturally colored cocoon resources of Bombyx mori, and introduced the production methods of colored cocoons, the development and utilization of naturally colored cocoon resources at home and abroad as well as the variety breeding instances, based on which suggestions were proposed for the development of colored cocoon industry.

Breeding of a Natural Colored-Cocoon Bombyx mori Variety Shuhuang No.1

[Objective] This study aimed to develop a new Bombyx mori variety Shuhuang No.1 and investigate its characteristics.[Method] The new variety was developed through cross breeding and pedigree separation.Its characteristics were identified by laboratory tests and rural promotion practices in Sichuan Province.[Result]The cocoon produced by the new variety Shuhuang No.1 was golden-yellow and radiantly beautiful.Shuhuang No.1 was strong and easy to rear,uniform in development.The male and female ones could be distinguished by their larval color and markings.The cocoon yield per 10 000 the 4th instar larvae reached 20.30 kg; the length of a cocoon filament was about 1 115.0 m,and a non-broken filament was 882.95 mm long,accounting for 79.15％ of the total length.The raw silk ratio of fresh cocoon was 18.39％,and the neatness was 91.25 point.The main economic features of Shuhuang No.1 were better than those of the control.[Conclusion] The new variety had been approved by Sichuan Silkworm Evaluation Commission.It can be promoted in parent silkworm rearing areas Sichuan,Chongqing,Yangtze River basin.

Molecular Detection of Healthiness of Bombyx mori

[Objective] The paper was to explore the regularity between heat shock protein expression and the healthiness changes of Bombyx moil materials. [Method] The representative heat shock protein gene Bmhsp24.3 was screened by bioinfor- matic analysis method, and carried out real-time PCR expression analysis. [Result] The target gene Bmhsp24.3 expressed in different B. mori materials, but the expres- sion level in different materials significantly varied. The relative expression level of the gene had different degrees of changes under different rearing conditions. With the increase of rearing temperature, the gene expression was upregulated. The ma- terials with better healthiness had remarkable increase in expression of target gene, while the materials with poorer healthiness had less increase in expression of target gene. The expression difference of target gene Bmhsp24.3 was exactly consistent with the healthiness of breeds. [Conclusion] The healthiness of materials had rela- tionship with expression of target gene Bmhsp24.3. the higher the expression of tar- get gene Bmhsp24.3 was, the better the healthiness of materials was; conversely, the lower the expression of target gene Bmhsp24.3 was, the poorer the healthiness of materials was.

关于桑蚕(BombyxmoriL.)对人工饲料摄食性的研究 Ⅱ.饲料的简易化制作和同一蚕品种对人工饲料摄食性的个体差异

为解决人工饲料育的发育不齐问题，就饲料的不同调制方法对桑蚕幼虫发育的影响，以及同一蚕品种个体间的差异进行了研究。结果发现：①在饲料制作上必须进行蒸煮灭菌，以微波炉加热灭菌的与蒸煮的效果相近，不经加热杀菌简易化制作的效果都不理想；②同一蚕品种个体间对人工饲料的摄食性存在差异。对桑叶粉及蔗糖等摄食促进物质的感受性，高食性蚕比低食性蚕敏感；而对豆粕粉中摄食阻碍物质的感受性，低食性蚕比高食性蚕敏感。研究认为，要提高人工饲料育蚕的群体摄食性和发育整齐度，应尽量消除饲料中的摄食阻碍物质。

Bombyx mori Pyridoxal Kinase cDNA Cloning and Enzymatic Characterization

Pyridoxal kinase （PLK） （EC 2.7.1.35） catalyzes the ATP-dependent phosphorylation of pyridoxal, generating pyridoxal-5＇-phosphate （PLP）, an important cofactor for many enzymatic reactions. Bombyx mori, similar to mammals, relies on a nutritional source of vitamin B6 to synthesize PLP. This article describes how a cDNA encoding PLK was cloned from Bombyx mori using the PCR method （GenBank accession number： DQ452397）. The cDNA has an 894 bp open reading frame and encodes a protein of 298 amino acid residues with a molecular mass of 33.1 k.Da. The amino acid sequence shares 48.6% identity with that of human PLK, and it also contains signature conserved motifs of the PLK family. However, the protein is 10 or more amino acids shorter than the PLK from mammals and plants, and several amino acid residues conserved in the PLK from mammals and plants are changed in the protein. The cDNA cloned was expressed successfully in Escherichia coli using the T7 promoter/T7 RNA polymerase expression system, and the crude extracts containing the expressed product were found to have strong PLK enzymatic activity with a value of 30 nmol/min/mg, confirming that the cDNA encodes the functional PLK of Bombyx mori. This is the first identification of a gene encoding PLK in insects.

Analysis of ESTs and gene expression patterns of the posterior silkgland in the fifth instar larvae of silkworm, Bombyx mori L.

The fibroin gene expression pattern and regulation of the posterior silkgland were studied by means of expressed sequence tags (ESTs) using the first and fifth day larvae of the fifth instar of silkworm, Bombyx mori L (strain: C 108). The results showed that there were 911 repetitive ESTs and 1950 single sequences (Singlets) among total 2861 consentient sequences, which were spliced. 1335 sequences were identified and the other 1526 were unknown. 5560 sequences (55.89%) in the posterior silkgland cell of the silkworm were new ESTs without homology with EST data published by Mita et al. The number of repetitive ESTs and single sequences from the first day larvae of the fifth instar was double more than that of the fifth day of the same instar in the silkworms. The unigenes which were more than 50 in repetitive EST size (contig size) came to only about 0.5% in total consentient sequences. There were significant differences between gene expression frequencies, and expressed genes were related to fibroin synthesis and its secretion and fibroin composition. Comparing the fifth day with the first day of the fifth instar, the genes-expressed quantity of fibroin heavy-chain gene was 18 fold higher, fibroin light-chain gene 9 fold and fibroin P52 gene 8 fold. 508 genes functioned for cellular component and 315 for enzyme after function tracing. These results implied that the gene expression of the first day was mainly for preparation for fibroin synthesis except for the growth of silkgland cells, and the gene expression of the fifth day of the fifth instar was mainly for synthesizing and excreting fibroin. Because the ratio of heavy chain, light chain and p25 of fibroin was not 6:6:1 as theoretically expected, or its special H-chain structure, the H-chain gene was not easy to detect through EST technique. Most of genes among total 2861 consentient sequences functioned for fibroin synthesis and secretion. This suggested the fibroin synthesis and secretion procedure of the posterior silkgland was more complex than the knowledge we have.

Biotransformation Effect of Bombyx Mori L. May Play An Important Role in Treating Diabetic Nephropathy

Compared with herbal drugs, medicine processed from animals(animal medicine) was thought to have more bioactive substances and higher activities. Biotransformation effect often plays an important role in their effect. However, researches about effect of animal medicine on diabetic nephropathy and applying animal medicine as natural bio-transformer were seldom reported. The purpose of this paper was to reveal the use of Bombyx Mori L. on diabetic nephropathy from ancient to modern times. The classical literature indicated that Saosi Decoction(缫丝汤), which contains Bombyx Mori L. or silkworm cocoon, was applied to treat disorders congruent with modern disease diabetic nephropathy from the Ming to Qing Dynasty in ancient China. Modern studies showed that Bombyx Mori L. contains four main active constituents. Among these, 1-deoxynojirimycin(1-DNJ) and quercetin showed promising potential to be new agents in diabetic nephropathy treatment. The concentrations of 1-DNJ and the activities of quercetin in Bombyx Mori L. are higher than in mulberry leaves, because of the biotransformation in the Bombyx Mori L. body. However, these specific components need further human and mechanistic studies to determine their therapeutic potential for this challenging condition.

Accumulation of 1-deoxynojirimycin in silkworm,Bombyx mori 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 significantly higher in blood,digestive juice,and alimentary canal,but no 1-DNJ was observed in the silkgland. Moreover,1-DNJ was not found in silkworms fed with artificial diet that does not contain mulberry leaf powder. This proves that silkworms obtain 1-DNJ from mulberry leaves; they could not synthesize 1-DNJ by themselves. The accumulation and excretion of 1-DNJ change periodically during the larval stage. There was no 1-DNJ in the newly-hatched larvae and 1-DNJ was mainly accumulated during the early and middle stages of every instar,while excreted at later stages of larval development. Further,it is possible to extract 1-DNJ from the larval feces and it is optimal to develop the 1-DNJ related products for diabetic auxiliary therapy.

Multiple Interval Mapping for Whole Cocoon Weight and Related Economically Important Traits QTL in Silkworm(Bombyx mori)

A backcrossed population （BC1） derived from a cross between C100 and Dazao was obtained. The quantitative trait loci （QTLs） of the economically important traits for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, etc., were analyzed for the first time using the multiple interval mapping software WinQTLCart2.0. In total 40 QTLs were detected and contributed to 21 groups based on the constructed linkage map. According to the mapping results, 2, 2, 3, and 2 major QTLs explained over 20% of total phenotypic variations, whereas four QTLs, namely qCW-19, qSW-2, qCSR-4, and qPW-23, explained more than 30% of total phenotypic variations for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, respectively. Correlated traits QTLs often share the same location. Furthermore, most of the detected QTLs were closed to one-side marker. By using the very closed markers, positive QTLs can be aggregated, which can form a basis for molecular marker-assisted selection and breeding.