Alternative splicing plays critical roles in controlling developmental programs. To date, there is evidence that many genes splice differently during gametogenesis. The regulation of alternative splicing occurs through a network of highly combinatorial molecular interactions. Numerous RNA binding proteins (RBPs) and transcription factors are involved in this process. Esrp1 (Epithelial Splicing Regulatory Protein 1) is a cell- type specific regulator. In the literature to date there have been no investigations into the expression and function of this gene during gametogenesis. As alternative splicing is a frequent event in the ovary and testis, we initiated studies to determine whether Esrp1 has a role in spermatogenesis and oogenesis. In the current study, we examined Esrp1 gene expression in mouse in developing germ cells and somatic cells. Esrp1 was expressed in germ cells but not somatic cells. Comparison of different developmental stages of spermatogenesis (gonocytes, spermatogonia, pachytene spermatocytes and round spermatids) using droplet digital PCR showed that ESRP1 is most highly expressed in spermatogonia. Consistent with this, immunofluorescence experiments to determine Esrp1 expression pattern of in adult testis showed distinct staining in spermatogonia. This distinct expression pattern for Esrp1 strongly suggests a specific a role for Esrp1 in promoting splicing events during spermatogonial development.