Development of the transgenic silkworm and its utilization.

1. 作为该基因转入家蚕体内的候选标记基因，我们分离并分析了一个编码肌凝素3-单加氧酶的基因，该基因是与普通色素合成有关的基因之一。该基因位于第10个连锁群上，与同群其他基因的重组值表明，该基因是突变白卵1.2的致病基因。利用分子标记（随机扩增的多态dna、已测序的基因等）对蚕性染色体和第10染色体进行结构分析。比较了两种性别家蚕Z染色体上基因mRNA的表达量，并比较了二倍体和三倍体个体间各种基因的表达量。结果表明，基因表达在家蚕体内不存在剂量补偿。对家蚕核多角体病毒（NPV）感染和多面体形成异常性状的基因进行了分离和分析。研究了染病家蚕幼虫血淋巴对npv的灭活效果，发现了一些与npv灭活效果呈正相关和负相关的因素。通过将标记基因转位到W染色体上建立的性别限制的标记幼虫，获得了一些具有标记的雄性幼虫，表明该基因发生了常染色体上的再转位。遗传分析表明，其中4个重易位标记基因位于第5（2例）、第6和第13染色体的一端附近。

1. As a candidate of a marker gene for then gene transfer into the silkworm, a gene encoding kynurenin 3-mono-oxygenase, which is one of genes concerning synthesis of ommochrome pigments, was isolated and analysed. This gene appeared to be located on the 10th linkage group and recombination value between it and other genes of the same group suggested that it is the causal gene of the mutant white egg 1.2. Molecular markers of the silk worm (random amplified polymorphic DNAs, already sequenced genes, etc.) were utilized for structural analyses of the sex chromosomes and the 10th chromosome.3. Amount of mRNA of genes on the Z chromosome were compared between two sexes of the silkworm, and comparison of expression of various genes between diploid and triploid individuals was also performed. Resuls showed that there is no dosage compensation of gene expression in the silkworm.4. Genes causing abnormal characters on the infection and polyhedron formation in the nucleopolyhedrovirus (NPV) of the silkworm were isolated and analysed. NPV-inactivation effect of hemolymph of infected silkworm larvae was investigated and some factors were appeared to concern the effect both positively and negatively.5. From the sex-limited larval marking strain, which was established by translocation of the marking gene onto the W chromosome, some male larvae with the marking were obtained showing that re-translocation of the gene onto autosome(s) occurred. Genetic analyses demonstrated that four of such re-tranlocated marking genes are located near to one end of the 5th (two examples), 6th, and 13th chromosomes.