家兔早期胚胎细胞发育能力的研究

THE STUDY OF THE DEVELOPMENTAL POTENTIAL OF EARLY EMBRYONIC CELLS OF RABBIT

本文利用胚泡注射法制作嵌合体对家兔交配后96,120和144小时的ICM细胞的发育能力进行了研究。供体胚胎取自青紫兰灰免,受体胚胎取自新西兰白兔,结果表明96和120小时供胚的ICM细胞与96小时受胚胚泡组合后均能参与发育,形成嵌合兔,144小时者未获得嵌合体。由于120小时的ICM细胞发育的2只表型为雄性的嵌合兔,其中1只不育,其性腺和外周血核型表明不育兔为xx/xy性嵌合,性腺中有处于不同发育程度的卵巢和精细管,外周血含xx和xy两种核型。本实验结果首次证明家兔交配后120小时胚泡的ICM细胞仍具有参与嵌合体发育的能力。它不仅能参与体细胞的分化,并具有形成生殖细胞的能力。交配后144小时胚泡的ICM细胞其发育能力似乎已发生了局限。

The developmental potential of rabbit embryonic cells was studied through making chimera by seperate introduction of inner cell mass from 96-h-old p. c., 120-h-old p. c., and 144-h-old p. c. of grey rabbits into 96-h-old p. c. blastocysts of New Zealand white rabbits. A total of five overt chimeras were obtained including two fertile male, two fertile females and one sterile male, from the ICM cells of 96-h-old and 120-h-old embryos but none was obtained from 144-h-old cells. Histological examination of the gonad showed that the sterile chimera derived from 120-h-old ICM cells with an ovotestis on both sides. Follicles and seminiferous tubules developed in the cortex and medulla of the gonad, respcctively. Neither of them developed into funtiohal germ cells. Analysis of karyotypes of pcriphcrial blood showed that both XX and XY coexisted in lymphocytes. These results indicated that the sterile male chimera was a XX/XY sex chimera derived from ICM cells of donor and recipients with different sex, so as to the chimera with XX and XY genotypic cells. From the results mentioned above we may conclude that the ICM cells at 120-h-old p. c. are still pluripotential, they can not only participate in development into somatic components but also develop into germ cells. The potential of 144-h-old p. c. ICM cells seems to be rather restricted.