DIFFERENTIAL EXPRESSION MECHANISMS OF HOUSEKEEPING AND LUXURY GENES DURING EMBRYONIC AND POST-EMBRYONIC DEVELOPMENT

从遗传学、形态学、生物化学和分子生物学等方面对家蚕的基因表达过程进行了研究，并对结果进行了全面的讨论。首先，分析了醛缩酶同工酶作为一个典型的管家基因系统的器官特异性表达。我们纯化了发现的两个同工酶，并利用获得的cDNA克隆证明了mRNA在胚胎发生过程中的发生模式，证实了醛缩酶同工酶在胚胎发生的关键时期在孵化前不久的转换。此外，本研究还对家蝇、人、七鳃鳗醛糖酶的酶学性质进行了比较。其次，成功分析了家蚕杆菌体液型胰蛋白酶抑制剂的多基因家族。特别感兴趣的是我们对精子发生和同源重组的基因网络的追求；利用与DMC1相互作用蛋白的cdna减法，我们在高等真核生物中首次分离到编码胞质和线粒体atp酶抑制蛋白、g蛋白调控蛋白等的克隆。第三，对九州大学保存的家蚕突变系，特别是与胚胎发生有关的突变系，进行了形态学和胚胎蛋白构成的研究。对家蚕的推定祖先——中国家蚕的多系染色体数目二态性进行了分析，并确定了地理分界线。总的来说，本项目获得的结果证实了家蚕作为分子和进化生物学的现代模式系统的地位。

The gene expression processes in Bombyx mori were examined in terms of genetics, morphology, biochemistry and molecular biology and results obtained were comprehensively debated. First, the organ-specific expression of aldolase isozymes, as a typical housekeeping gene system, was analyzed. Two isozymes we have found were purified and the mode of occurrence of mRNA during embryogenesis was demonstrated using a cDNA clone obtained, confirming the switchover of aldolase isozymes at a critical period of embryogenesis shortly before hatching. Moreover, the enzymatic properties of the silkworm aldolases were compared with those from the housefly, human and lamprey also investigated in the present study. Second, the luxurious multigene families for the humoral trypsin inhibitors of B. mori were successfully analyzed. In particular of interest were our pursuit for the gene network underlying the spermatogenesis and homologous recombination ; the subtraction method of cDNAs for the proteins interacting with DMC1 led us to isolate clones encoding cytoplasmic and mitochondrial ATPase inhibitor proteins, G-protein regulatory protein etc., for the first time in higher eukaryotes. Third, the B. mori mutant lines in particular those related to embryogenesis, stored in Kyushu University, were investigated for morphology and embryonic protein constitutions. We also analyzed the chromosome number dimorphism using many lines of Bombyx mandarina, which is putative ancestor of B. mori, and confirmed the geographical borderline. As a whole the results obtained in the present project have verified the status of B. mori as a modern model system of molecular and evolutional biology.