Grafting Period and Donor Age Affect the Potential for Spermatogenesis in Bovine Ectopic Testis Xenografts
Grafting Period and Donor Age Affect the Potential for Spermatogenesis in Bovine Ectopic Testis Xenografts
复制标题
移植期和供体年龄影响牛异位睾丸异种移植物的精子发生潜力
作者：
Jonathan A. Schmidt;J. Avila;D. Mclean
摘要 牛睾丸组织异种移植物在移植后 6 个月内含有伸长的精子细胞。移植物切除时，生精小管横截面中精子细胞伸长的百分比随供体年龄的不同而变化，很少超过 10%。这些数据表明，在生命的最初几周内，牛睾丸细胞正在发生显着的变化。本研究的目的是将来自多个年龄段的小牛的睾丸组织异种移植 24 或 36 周，以便更好地了解早期牛睾丸发育。将 1、2、4 和 8 周龄小牛的睾丸组织移植到去势的免疫缺陷小鼠的背部。所有供体年龄的睾丸组织都生长、分化并产生睾酮和伸长的精子细胞。无论移植时期如何，在移植物去除时，来自 1 周和 8 周龄小牛的睾丸组织移植物在超过 5.5% 的生精小管横截面中具有伸长的精子细胞。四周大的供体组织从未有超过 5.2% 的生精小管横截面具有伸长的精子细胞。将移植期从 24 周延长至 36 周，导致 2 周供体组织中生精小管横截面中精子细胞伸长的百分比从 2% 增加到 10%。这些数据表明供体年龄和移植时期可能是调节牛睾丸异种移植物成熟的重要因素，表明这些供体年龄的睾丸组织内存在内在差异。这些数据为利用异位睾丸异种移植进一步研究牛精子发生提供了框架。
Abstract Bovine testis tissue xenografts contain elongating spermatids 6 mo after grafting. The percentage of seminiferous tubule cross sections with elongating spermatids at the time of graft removal varies depending on donor age and rarely exceeds 10%. These data indicate significant changes are occurring to bovine testicular cells during the first weeks of life. The objective of this research was to xenograft testis tissue from multiple ages of bull calves for 24 or 36 wk in order to gain a better understanding of early bovine testis development. Testis tissue from 1-, 2-, 4-, and 8-wk-old calves was grafted onto the backs of castrated immunodeficient mice. Testis tissue from all donor ages grew, differentiated, and produced testosterone and elongating spermatids. Testis tissue grafts from 1- and 8-wk-old calves had elongating spermatids in greater than 5.5% of seminiferous tubule cross sections at the time of graft removal regardless of grafting period. Four-week-old donor tissue never had more than 5.2% of seminiferous tubule cross sections with elongating spermatids. Extending the grafting period from 24 to 36 wk resulted in an increase in the percentage of seminiferous tubule cross sections with elongating spermatids from 2% to 10% in 2-wk donor tissue. These data demonstrate that both donor age and grafting period may be important factors regulating the maturation of bovine testis xenografts, indicating that intrinsic differences exist within testis tissue at these donor ages. These data provide the framework for further study of bovine spermatogenesis using ectopic testis xenografting.