Page 16 - X. Stem cell biology

[X. Stem cell biology-10]

Identification of novel cell surface markers on spermatogonia

stem cells

Jee Seung Kim¹˙#, Jin Seop An²˙#, Hyun Min Lee¹, Beom-Jin Shin², Buom-Young Ryu²˙*, Chun Jeih Ryu¹˙*

¹Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul 05006, South Korea,

²Department of Animal Science and Technology, Chung-Ang University, Gyeonggi-Do 17546, South Korea

Spermatogonial stem cells (SSCs) are specialized stem cells that maintain sperm production at seminiferous tubules
throughout the reproduction life of male mammals. The sorting of SSCs is critical for the therapeutic application of

male infertility, but there are no reliable SSC surface markers. Here, we investigated new SSC markers that show the

specificity to SSCs. By flow cytometry of mouse SSCs and STO cells with 255 antibodies, we identified eight
candidates as new surface markers for SSCs. We investigated their expression levels on cultured germ cell enriched
for SSC (GCES) lines and primary SSCs. The eight candidates were highly expressed in both cultured GCES and

primary SSCs. Among these, CD71 and PLXN B2 were well colocalized with the known SSC surface markers. To
study the functional role of two candidates on SSCs, we knocked down the genes in cultured GCES lines and then

analyzed the expression of stemness and differentiation markers. We also sorted the pup testis cells with anti-CD71
and anti-PLXN B2 antibodies and transplanted the positive and negative cells into busulfan-treated recipient mouse

testes to evaluate SSC activity of sorted cell populations. The functional characterization of the new candidate
markers is now under investigation.