早期人胎儿睾丸组织异种异体生长发育的研究

目的 采用免疫缺陷小鼠为受体的睾丸组织移植技术，探索小于3月龄的人类胎儿未成熟睾丸组织在异种异位生长发育的可行性，为睾丸移植技术用于人类生精机制研究提供更为易行的供体来源。 方法 将9例10～13周流产胎儿的睾丸组织分别移植到6只雄性去势免疫缺陷小鼠背部皮下，根据移植物的生长状态以及受体的健康状况于不同时间取出移植物。通过对睾丸组织移植前后的组织学观察，对人类未成熟睾丸组织在异种异位的生长发育情况进行分析。 结果 3个月左右的胎儿睾丸约为5～7mg，移植后取出的最大移植物重量为84.1mg。9例未成熟睾丸组织移植后观察到有6例在受体中继续生长发育，其中的生精小管直径由移植时的(44.26±3.14)μm发育成为(77.69±7.47)μm。小管中无规则分布的原始生殖细胞和原始支持细胞开始向基底膜部位迁移，其中部分原始生殖细胞已定位于基底膜处，并具有精原细胞的特征；支持细胞也由幼稚状态发育为具有丰富胞质的成熟型细胞，有序排列在精原细胞周围，形成壁龛样结构。 结论 将较易获得的早期流产胎儿睾丸组织移植到免疫缺陷小鼠体内后，睾丸组织可继续生长发育，因此可作为人类睾丸组织生长发育研究的供体组织。

Development of early human fetal testes after xenografting into mice

Objective To investigate the developmental feasibility of early human fetal testes (<3 months) using xenografting technique and to acquire an accessible donor derivation that is essential for studying human germ cell development. Methods Nine testes from 10-13 weeks aborted fetus were grafted under the back skin of 6 castrated nude mice. Grafts were collected at different time point according to the growth of the donor tissues and the health condition of the recipients. Morphological and histological analyses were performed for the observation of the development of grafted immature testicular tissues. Results The mass of grafts was increased from about 5-7mg to 84.1mg (the biggest). Six of 9 testes were to be in developing. Histological observations showed a significant expansion of seminiferous tubules from (44.26±3.14)μm to (77.69±7.47)μm. Cells dispersedly distributed in seminiferous cords at the time of grafting migrated towards the basal part of seminiferous epithelium. Some germ cells with spermatogonium-like characteristics located on the basement membrane. Sertoli cells were in stages from immature into matured with abundant cytoplasm which were orderly arranged around spermatogonia forming a niche-like structure. Conclusion Testes from early aborted human fetus grafted under the back skin of castrated nude mice showed further development and therefore could be used as an easier accessible donor tissues for the investigation of human spermatogenetic mechanism.