Primate spermatogonial stem cells colonize mouse testes

M Nagano1, J R McCarrey, R L Brinster

  • 1Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6009, USA.

Insights

Baboon stem cells successfully colonized mouse testes, but did not produce sperm. This suggests key molecules for sperm development diverged significantly between baboons and mice over evolutionary time.

Area of Science:

  • Reproductive Biology
  • Stem Cell Transplantation
  • Comparative Genomics

Background:

  • Spermatogonial stem cell transplantation is a method for studying germ cell development and fertility.
  • Previous attempts to transplant human testis cells into mice yielded conflicting results regarding germ cell survival and differentiation.
  • The baboon serves as a valuable model for studying primate reproductive biology due to its phylogenetic proximity to humans.

Purpose of the Study:

  • To investigate the survival and differentiation potential of baboon spermatogonial stem cells (SSCs) following transplantation into infertile mouse testes.
  • To explore the evolutionary conservation of factors necessary for SSC survival and spermatogenesis between primates and rodents.

Main Methods:

  • Transplantation of baboon testis cells into seminiferous tubules of recipient mice.
  • Long-term monitoring of donor cell survival and differentiation using histological and molecular analyses.
  • Comparative analysis of conserved and diverged molecular interactions between baboon and mouse testis environments.

Main Results:

  • Baboon SSCs successfully engrafted and formed colonies in mouse seminiferous tubules, persisting for at least six months.
  • Donor germ cells did not differentiate towards the tubule lumen or produce spermatozoa.
  • The long-term survival of baboon SSCs indicates conserved factors for stem cell maintenance between species separated by 100 million years.

Conclusions:

  • Essential factors for spermatogonial stem cell survival and self-renewal are conserved between baboons and mice.
  • The lack of germ cell differentiation suggests that molecules regulating spermatogenesis have diverged significantly between these species.
  • This study highlights the evolutionary divergence in the molecular mechanisms governing mammalian spermatogenesis.