Mouse testicular gene expression pattern differences between spermatogonial stem cell proliferative and differential stages

Abstract

Objective To detect the mouse testicular gene expression pattern differences be-tween spermatogonial stem cell (SSC) proliferative and differential stages and study the molecular reg-ulation mechanism in SSC proliferation and differentiation. Methods With the interval of 24 days, male Kunming mice were injected intraperitoneally with two doses of busulfan (10 mg/kg) to establish spermatogenesis regeneration models. 36 k Mouse Genome Array was used to detect the differential gene expression profiles between the stages of SSC proliferation and differentiation. Bioinforrnsties analysis was conducted in GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Ge-nomes) pathway to describe the potential roles that may play in spermatogonial stern cells behavior regulation. Results Nine hundred and eleven differential expression genes were identified by gene arrays in mice testes, consisting of 608 up-regulated and 303 down-regulated in SSC proliferation stage and SSC differentiation stage. The differential expression genes were classified by their biological process, molecular function and cellular component, respectively. Alterations with statistical signifi-cance (P<0.05)appeared in 84 KEG(;signal pathways, including Notch and Wnt signaling pathways which had been proved to be important for stem cell maintenance. Fifty-six differential expression genes were selected as genes related to stem cells, among which 40 genes were up-regulated, including some stem cell biomarkers(such as Cd9, StraS, hgbl-, Oct4 and Thyl)and some growth factors(such as Fgf2, Pdgfa and Csfl). Conclustion The regulation of SSC proliferation and differentiation involves inmany differentially expressed genes in various signal pathways. This study provides a molecular basis for the elucidation of the molecular mechanism behind self-renewal and differentiation of spermatogonial stem cells. Key words: Spermatogonia stem cells; Proliferation; Differentiation; Gene array