The hypoxia-inducible factor EPAS1 is required for normal spermatogonial stem cell function in regenerative conditions [EPAS1 scRNAseq]

To understand the role of the hypoxia-inducible transcription factor EPAS1 in regulating spermatogonial stem cell (SSC) function, a conditional knockout mouse was generated (EPAS1-cKO) where Epas1 was ablated only in the germ cells (Ddx4-Cre, Epasfl/-). For single cell RNA sequencing analysis, control and EPAS1-cKO males were pre-treated with the chemotherapeutic reagent busulfan to instigate regenerative conditions, and a germ cell-enriched cell population was collected 14 days later. Transcriptome profiling revealed that EPAS1 deficiency alters gene expression and key cellular processes in undifferentiated spermatogonia, including metabolism and proteostasis. Overall, these transcriptomic changes resulted in an impaired capacity for SSCs to restore spermatogenesis after busulfan treatment. Overall design: Comparing germ cell populations from the testes of control mice to mice with germline ablation of Epas1. Mice were treated with busulfan (20mg/kg) 14 days prior to analysis to instigate regenerative conditions.