scRNA-seq reveals different cell clusters in the testes of Mongolian cattle and EGR1/FOS/JUN regulation in Sertoli cells.

Mongolian cattle maintain stable reproductive performance under long-term cold and nutrient-limited conditions, but the molecular basis of their testicular function remains unclear. In this research, a single-cell RNA-sequencing (scRNA-seq) atlas of Mongolian cattle testes was generated and analyzed. The results showed that scRNA-seq identified major germ and somatic cell types, in particular Sertoli cells, which was composed of four subclusters representation different developmental stages. Transcriptomic analysis and pseudotime reconstruction indicated that Early Growth Response 1 (EGR1) might be a potential regulator of Sertoli cell maturation. To investigate the function of EGR1 in Sertoli cells, the methods of siRNA knockdown, overexpression, immunohistochemistry, and ChIP–qPCR were used and the results showed that EGR1 could directly bind to and activate FOS and JUN, joining an EGR1–FOS/JUN-Nectin-2 regulatory pathway in Sertoli cells to maintain the reproductive capacity. The results provided insights into the cellular and molecular mechanisms underlying the reproductive performance of Mongolian cattle.