Two Bombyx mori isoforms of the gene lark, which is shown to play an important role in Drosophila circadian rhythms, were identified and named Bmlark-PA and Bmlark-PB, respectively. Bmlark-PA consists of 5 exons and encodes a protein of 343 amino acid residues which contains 3 functional domains: two RRM (RNA recognization motif) domains and an RTZF (retroviral-type zinc finger), and shares 72% identity with the Drosophila gene lark at the amino acid level. Bmlark-PB lacks the sequence between 118 and 791 nt of Bmlark-PA and codes for a protein of 68 amino acid residues, which contains no distinct functional domains. Alignments of the cDNAs of Bmlark to the genomic draft sequence of B. mori showed that the gene Bmlark had a single copy in the genome, suggesting that an alternative splicing mechanism occurs in the gene Bmlark. RT-PCR analysis indicated that Bmlark-PA was expressed only in late pupae and adult but Bmlark-PB was broadly expressed in many tissues and throughout the developmental stages from embryo to adult.

The fat body plays key roles in metabolism and sustenance of growth throughout the life of a silkworm, and thus represents a model tissue for studying development and metamorphosis. Analysis of 18480 ESTs derived from larval and pupal fat body cDNA libraries allowed characterization of gene expression patterns in the fat body during metamorphosis. By Phrap assembling, 6814 estimated transcription units (TUs) were generated, 2673 of which contained 60% of the total ESTs and represented 1366 distinctive known genes. These genes were classified into 14 categories based on their known or putative functions, and most were found to be involved in metabolism and cell defense. Further comparative analysis of the expression profiles revealed that the gene expression patterns in the larval fat body strikingly differed from those in the pupal fat body. From this, we identified a subset of genes potentially associated with metamorphic events such as the formation or destruction of specific tissues, and simultaneously confirmed the stage-specific expression patterns of several identified genes using RT-PCR examination. This work will provide a valuable resource for studying regulatory mechanisms associated with fat body developmental changes and silkworm metamorphosis.

通过导入特定基因的dsRNA特异性地关闭该基因的功能，由此产生的现象为RNA干涉。为在家蚕胚胎发育时期建立有效的RNAi技术体系，在前人的基础上以家蚕第三白卵基因Bmuh3为材料，建立了有效的RNAi技术体系，结果表明，成功诱导第三白卵突变表型的有效注射时间为产卵后8h内，wh3dsRNA的有效浓度须大于2.0g/L。在发育胚胎的第三天注射wh3dsRNA，同样可诱导第三白卵突变的另一表型——半透明蚁蚕，根据实验结果初步推测，Bmwh3不仅参与眼色素和卵浆液膜色素前体的转运，还可能参与胚胎体壁色素前体的转运。

为了研究家蚕Bombyx mori卵中储存的母性遗传信息，以未受精的肾脏型和正常型蚕卵为材料构建了cDNA文库，并对其随机测序，共获得391条表达序列标签（EST）序列，经拼接后得到374条非重复序列。生物信息学分析发现，172个非重复序列与国际数据库GenBank和silkbase中的已知基因具有较高的相似性。除3个已知母性基因外，其余主要与DNA复制、能量代谢、信号转导、转录、蛋白质结构以及胚胎发育中个体形成等相关：该结果可为进一步研究家蚕胚胎早期发育的调控提供基础数据。

胰凝乳蛋白酶抑制剂（Chymotrypsin inhibitor,CI）是家蚕血液中主要的蛋白酶抑制因子，为其正常生长发育所不可缺少，研究a对阐明家蚕正常生理以及害虫防治等都具有重要意义。采用pH8.3、4.0聚丙烯酰胺凝胶电泳和CI活性染色法，对6个家蚕品种血液中的蛋白质含量和CI活性进行了测定，并对各品种CI活性的个体差异性进行了分析。结果表明：结合pH 8.3和pH4.O的电泳条件，可检测出Ict-D，Ict-E，Ict-A，Ict-B，Ict-H基因所支配的15种CI；6个品种中有3个具有CI个体差异性，而且Ict-E和Ict-B在有的品种或个体无活性，为非必需种类。