【摘要】 为了调查家蚕性连锁平衡致死系中Z染色体携带致死基因l2的雌性胚子(简称l2胚子)致死的时间和原因,收集家蚕性连锁平衡致死系品种平2不同胚胎发育时期的雌性黑卵,解剖获取胚胎后用光学显微镜对不同发育时期的l2胚子进行组织形态学观察。形态观察可见l2胚子在胚胎发育早期和能正常发育的雌性胚子没有区别,但l2胚子发育至晚期的己2期,约有一半胚子的体表未能正常着色,因此推断那些仍没有正常着色的胚子即为致死的l2胚子。通过胚胎的半薄切片观察发现,己2期l2胚子的组织器官结构完整,与正常发育的雌性胚子之间无明显的差异。观察结果提示:l2胚子死亡可能不是由于胚胎组织结构异常造成的,有可能是在己2期胚子停滞发育致死。更多还原

【Abstract】 In order to investigate the time and causes of death of the female embryos carrying the lethal allele l2 on the Z chromosome (hereinafter referred to as l2 embryos) in a sex-linked balanced lethal silkworm (Bombyx mori) strain,the black female eggs of a sex-linked balanced lethal silkworm strain named Ping 2 were collected at different developmental stage and histomorphological observations were conducted to l2 embryos of various developmental stages by optical microscopy after the embryos were obtained through dissection. The results showed that there was no difference between l2 embryos and normal embryos at the early embryonic developmental stage. However,when the embryos developed into the completion stage of embryonic reversal,the body surfaces of about half of them were not colored normally,suggesting that these embryos without normal color were the lethal l2 embryos. The observation on semithin sections of the female embryos showed that at the completion stage of embryonic reversal,structural integrity of tissues and organs of l2 embryos were not damaged,and no obvious difference was found in tissue structures between l2 embryos and normal embryos. These results suggest that the death of l2 embryos were due to the arrest of embryonic development rather than the abnormality of embryonic tissue structures.更多还原