Study on evolution of the silkworm and its application to biotechnology

1.采用脉冲场梯度电泳技术，在P_（1-x）品系中检测到一条家蚕染色体片段<sm>，并在凝胶上检测到2条DNA带，为细胞核DNA的特异带.家蚕（Bozbyx）和家蚕（B）的核仁组织者。并根据二者的差异对家蚕的进化进行了探讨.研究了嵌合基因在家蚕MO系受精过程中的作用，提出了几种解释异常受精的修正模型.家蚕品系对两种浓核病毒的非亲和性受两个独立的基因控制.在无基因产生的花叶家蚕中肠上皮细胞中观察到浓核病毒的花叶感染.家蚕和蓖麻蚕的芳基荧光素在血清学和化学性质上相似，但在发育过程中的动态变化不同.检测了家蚕浓核病病毒2型感染后中肠RNA的体外翻译，并对病毒颗粒的多肽进行了检测.桑葚的非封闭病毒与家蚕浓核病毒和家蚕脆性病毒在血清学上无明显区别，桑螟可能是这些病毒的共同习惯宿主。家蚕早期幼虫卵巢离体培养时，脑中的激素是卵母细胞分裂和发育所必需的。牛胎血清影响Boabyx细胞系对核型多角体病毒的易感性。家蚕卵巢卵黄发生受蜕皮激素调节。

1. A fragmentary chromosome of the silkworm was detected in P^<sm> strain by pulse-field-gradient-electrophoresis, and 2 DNA bands on the gel were specific to DNA in the nuclei.2. Nucleolus organizers in the wild silkworm, Bozbyx mandarins and the domesticated silkworm, B. mori were compared and evolution of the silkworm was discussed based on their differences.3. Action of mosaic gene on the fertilization in MO-strain of the silkworm was examined and several modified models to explain the abnormal fertilization was proposed.4. Nonsusceptibilities of the silkworm strains to two densonucleosis viruses were controlled by two independent genes.5. Mosaic infection with a densonucleosis virus was observed in the midgut epithelium of the mosaic silkworm which was produced by no gene.6. Arylphorins from Bosbyx mori and Samia cynthia ricini resembled each other in the serological and chemical nature but their dynamics during the development was different.7. In vitro translation of RNA from the midgut infected with Boabyx mori densonucleosis virus type-2 was examined and peptides of virus particles were detected.8. Nonoccluded viruses of the mulberry pyralid were serologically indistinguishable from densonucleosis viruses and fracherie virus of the silkworm and the pyralid was supposed to be a common habitual host of these viruses.9. When ovaries from the silkworms at the early larval stages were cultured in vitro, the hormones from the brain were necessary to cell division and development of the oocytes.10. Bovine fetal serum affected the susceptibility of a Boabyx cell line to a nuclear polyhedrosis virus.11. Vitellogenic development of the ovary of the silkworm, Bowbyx mori was regulated by ecdysteroids.