H3K4me2 cooperates with Wnt/TCF7L2 to regulate TDRD1 and promote chicken spermatogonia stem cell formation

Spermatogonia Stem Cells (SSCs) are the basis of spermatogenesis. In the poultry industry, asthenospermia and azoospermia in roosters seriously reduce economic benefits. In this study, we explored SSCs formation mechanisms in detail. TDRD1, which is a downstream target gene of TCF7L2 and is modified by histone methylation, was screened through multiomics analysis. Functionally, RT-qPCR, flow cytometry, immunohistochemistry, and indirect immunofluorescence results showed that H3K4me2 regulated TDRD1 to promote SSCs formation both in vivo and in vitro. Furthermore, ChIP-qPCR and dual luciferase assays showed that H3K4me2 was enriched in the -800 to 0 bp region of the TDRD1 promoter and positively regulated TDRD1 transcription to promote SSCs formation. Interestingly, in mechanistic terms, dual luciferase assays showed that TDRD1 transcription levels were significantly decreased after co-transfection with dCas9-LSD1-P1/P2/P3 and OETCF7L2, while TDRD1 transcript levels were not significantly altered after transfecting dCas9-LSD1-P4 and OETCF7L2. These results suggested that H3K4me2 enrichment in P1, P2, and P3 of the TDRD1 promoter promotes TDRD1 transcription by reducing enrichment of TCF7L2. This study explored the specific regulatory mechanisms involving the Wnt signaling pathway, H3K4me2, and TDRD1, enriched the regulatory network regulating the formation of SSCs, and laid a theoretical foundation for the specific application of SSCs.