Department of Veterinary Anatomy, The University of Tokyo, Tokyo, Japan.
Dev Dyn. 2012 Aug;241(8):1374-84. doi: 10.1002/dvdy.23824. Epub 2012 Jul 9.
The spermatogonial transplantation experiment can be used as an unequivocal detection assay of spermatogenic stem cells (SSCs) in both a qualitative and quantitative manner, based on their regenerative capacity. In this study, the proliferative patterns and kinetics of donor-derived GFRα1-positive spermatogonia containing potential SSCs were examined during early colonization following spermatogonial transplantation.
Donor-derived GFRα1-positive cells frequently formed several aggregates of A(al(aligned)) /morula-like structures in a single spermatogenic cell patch before and on day 14 post-transplant, indicating a possible involvement in the formation of a stable spermatogenic colony at 21 days post-transplant. The appearance of these A(al) /morula-like aggregates is positively correlated with regional, high-level expression of immunoreactive GDNF signals, a ligand for GFRα1, associated with colony expansion.
These data raise the hypothesis that regional GDNF signals regulate the balance between donor-derived A(al) -like cell aggregates and their differentiation in each small patch, which subsequently leads to further selection of survival colonies at later stages.
基于再生能力，精原干细胞（SSC）的移植实验可以定性和定量地用作精原细胞的明确检测分析。在这项研究中，在精原细胞移植后早期定植期间，检查了含有潜在 SSC 的供体衍生的 GFRα1 阳性精原细胞的增殖模式和动力学。
在移植前和移植后 14 天，供体衍生的 GFRα1 阳性细胞经常在单个生精细胞斑中形成多个 A(al(对齐))/桑椹胚样结构的聚集，表明其可能参与形成稳定的生精集落在移植后 21 天。这些 A(al)/桑椹胚样聚集的出现与 GDNF 信号的区域高水平表达呈正相关，GDNF 信号是 GFRα1 的配体，与集落扩张有关。
这些数据提出了一个假设，即局部 GDNF 信号调节供体衍生的 A(al)样细胞聚集及其在每个小斑中的分化之间的平衡，随后导致在后期阶段进一步选择存活集落。
