Vast amounts of sperm are produced from spermatogonial stem cells (SSCs), which continuously undergo self-renewal. We examined the possible effect of laterality in male germline transmission efficiency of SSCs using a spermatogonial transplantation technique. We transplanted the same number of wild-type and Egfp transgenic SSCs in the same or different testes of individual recipient mice and compared the fertility of each type of recipient by natural mating. Transgenic mice were born within 3 months after transplantation regardless of the transplantation pattern. However, transgenic offspring were born at a significantly increased frequency when wild-type and transgenic SSCs were transplanted separately. In addition, this type of recipient sired significantly more litters that consisted exclusively of transgenicmice, which suggested that left and right testes have different time windows for fertilization. Thus, laterality plays an important role in germline transmission patterns from SSCs.

Summary Sentence

Nonrandomness of germline transmission pattern of spermatogonial stem cells was examined by spermatogonial transplantation.