胎儿睾丸组织异种移植后生精细胞发育初探

目的 :以人胎儿睾丸组织为供体 ,免疫缺陷小鼠为受体 ,研究人类睾丸生精细胞异种移植后的继续发育情况。　方法 :将 2 6周胎儿的睾丸组织植入去势裸鼠背部 ,于移植后 1 35d取出移植物 ,进行组织形态学观察 ,分析原始生精细胞在异种异位的发育情况。　结果 :移植 1 35d后取出的移植物显示 ,其生长幅度已由移植前直径约 1mm和湿重约 5mg ,分别增加到移植后大于 3mm和 2 0mg。组织形态学观察发现 ,移植前的睾丸主要是由直径为(6 0± 1 5 ) μm的精曲小管索构成 ,其中包含的细胞主要是原始Sertoli细胞和少量原始生精细胞 ,细胞排列呈弥散无规则状态 ;而移植后 1 35d的精曲小管索已发育成具有管腔的精曲小管 ,出现由Sertoli细胞和生精细胞组成的完整生精上皮 ,直径增大到 (80± 2 5 ) μm。原本呈不规则分布的原始Sertoli细胞和生精细胞大部分已迁移到基膜处 ,其中有少数生精细胞发育成为精原细胞。　结论 :人胎儿睾丸组织移植到去势裸鼠背部后 ,可以继续存活并进一步生长发育。

Preliminary Study on the Development of Germ Cells from Human Fetal Testicular Tissues Xenografted into the Mouse

OBJECTIVE: To investigate the development of xenografted primitive human germ cells by using fetal testicular tissues as donor tissues and an immunodeficient mouse as the recipient. METHODS: Testicular tissue fragments of a 26-week fetus were grafted under the back skin of a castrated immunodeficient mouse. Grafts were taken out after 135 days and processed for morphological and histological analyses. RESULTS: The mass of grafts grew from about 1 mm in diameter and 5 mg in wet weight to about 3 mm and more than 20 mg 135 days after grafting. Histological observations showed a significant expansion of seminiferous tubules after grafting (80 +/- 25 microm in diameter) in comparison with seminiferous cords at the time of grafting (60 +/- 15 microm in diameter). The seminiferous cords developed into seminiferous tubules with the epithelial border and lumen. After 135 days of grafting, most of the dispersedly distributed primitive Sertoli cells and germ cells migrated to the basal part of seminiferous epithelium, located on the basement membrane and few of germ cells differentiated into spermatogonia. CONCLUSION: Human fetal testicular tissues could survive and continuously develop after being xenograft into castrated immunodeficient mice.