THY1 IS A CONSERVED MARKER OF SPERMATOGONIAL STEM CELLS IN THE PRE-PUBERTAL BULL TESTIS
Open Access
- Author:
- Reding, Suzanne Christine
- Graduate Program:
- Animal Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- August 17, 2009
- Committee Members:
- Jon M Oatley, Thesis Advisor/Co-Advisor
Jon M Oatley, Thesis Advisor/Co-Advisor - Keywords:
- spermatogonnial stem cell
seminiferous tubule
spermatogonia - Abstract:
- Spermatogonial stem cells (SSCs) are the precursors of sperm and their ability to self-renew and differentiate provides the foundation for sustaining spermatogenesis. Culture and transplantation of SSCs in bulls has the potential to enhance the efficiency of cattle production and provide a novel avenue for generation of transgenic animals. Because of their rarity, these techniques depend on the ability to isolate SSCs from the total testis cell population. However, this capability is currently unavailable for any livestock species. In both the mouse and nonhuman primate, SSCs express the cell surface molecule Thy1 and selection of Thy1+ cells from the total testis cell population results in SSC-enrichment. In this study, the hypothesis that Thy1 is a conserved marker of SSCs in the bull testis was tested. Flow cytometric analysis showed that the Thy1+ cell fraction comprises a rare subpopulation of cells in the testis of prepubertal bulls. Next, Thy1+ cells were isolated from prepubertal bull testes using magnetic activated cell sorting (MACS) and further examined for characteristics of the proliferating spermatogonial population. Expression of Plzf, a transcription factor expressed exclusively by proliferating spermatogonia, was highly enriched in isolated Thy1+ cells compared to the unselected total testis cell population. Further analysis revealed that the majority of cells in the isolated Thy1+ testis cell population are Plzf+. Lastly, xenogeneic transplantation of bull testis cells into seminiferous tubules of immunodeficient nude mice resulted in a greater than 6-fold increase of germ cell colonies from Thy1+ cells compared to the unselected total testis cell population. Collectively, these results demonstrate that Thy1 is a marker of SSCs in the prepubertal bull testis and isolation of Thy1+ cells produces an SSC-enriched fraction compared to the total testis cell population.