对鸡胚视网膜细胞DNA合成的放射自显影研究

目的　研究鸡胚视网膜细胞发生过程中的形态变化与DNA合成代谢的关系。 方法　应用光镜放射自显影技术,对 1, 2, 3, 4, 7d鸡胚视网膜氚标胸腺嘧啶的分布进行观察。 结果　随胚龄增加氚标胸腺嘧啶的银颗粒数,在视杯后部由多到少,而在视杯前部则由少到多,均以 2d胚达高峰。胚龄早期各部银颗粒数外层多于内层;但胚龄晚期则内层增多,外层消失。 结论　视网膜细胞的分化成熟由后部移向前部,视细胞和视神经细胞分化较早;伴随视网膜细胞的分化成熟,DNA的合成数量和区域分布表现为动态变化。

Radioautographic study on deoxyribonucleic acid synthesis in the retina of chick embryo

Objective To explore the relationship between morphologic change and DNA synthesis during the development of retina of chick embryo. Methods The distribution of thymidine 3 H in retina anlagen of chick embryo on day 1,2,3,4,7 was studied by the means of light microscopic radioautography. Results With the increase of age of embryo,thymidine 3 H labled positive granule counts were gradually decreased in the posterior and increased in the anterior of optic cup,and reached a high peak on day 2.In the earlier period of embryo,the positive granule counts of each region were more in retinal outer layer than in retinal inner layer,and later,the positive granule were gradually increased in retinal inner layer and disappeared in retinal outer layer. Conclusion Retinal cells differentiate and mature in retinal posterior region at first and then in the anterior,and during this interval,the DNA synthesis and distribution show a dynamic change.