胚胎及生后不同发育时期大鼠睾丸生殖细胞的凋亡

APOPTOSIS OF GERM CELLS IN RAT TESTIS DURING FETAL AND POSTNATAL DEVELOPMENT

目的 探索雄性生殖细胞在发育过程中凋亡的特征和规律。方法 利用改进的石蜡切片原位末端标记法(TUNEL法 )观察SD大鼠睾丸生殖细胞 ,对胚胎及生后不同阶段生殖细胞凋亡进行研究。结果 胚胎第 13 5天原始生殖细胞即有较高的凋亡率 ,胚胎第 19 5天到出生后第 1天 ,未检测到凋亡生殖细胞。出生后第 7天精原细胞分裂增生 ,伴有较高的凋亡率 ,与其他各年龄组有显著性差异 ,出生后第 14天精母细胞凋亡率最高 ,与其他日龄组有显著性差异。结论 SD大鼠雄性生殖细胞发生、发育、成熟过程中都存在凋亡 ,主要发生在处于细胞增殖过程中的原始生殖细胞、精原细胞和初级精母细胞。

Objective To study the apoptotic germ cells in testis during fetal and postnatal development. Method SD rat testis taken from day 13.5 post coitum to day 56 post partum were studied for the detection of the cell types and extent of apoptotic germ cells by modified TUNEL method. Result There was a relatively high level of prespermatogonia apoptosis at day 13.5 post coitum (4.59±4.20 per 100 germ cells), followed by the same level during their proliferation, but such apoptosis ws hardly seen at day 19.5 post coitum and day 1 post partum. At day 7 post partum, when spermatogonia differentiated and proliferated, there was another high apoptosis wave (8.89±5.84 per 100 germ cells),and there was no statistic difference between day 13.5 post coitum and 7 post partum. We found an apoptosis peak. At day 14 post partum when spermatocytes had been developed. From then on spermatogonia and spermatcytes remainat a low level of apoptosis. Conclusion Apoptotic germ cells exist in the SD rat testis during fetal and postnatal development. There are different apoptotic levels according to different periods of development. The main apoptotic cell types are prespermatogonia, spermatogonia and spermatocytes.