EWSR1 is critical for post-meiotic transcription and spermiogenesis

Spermatogenesis is precisely controlled by complex gene expression programs. During mammalian male germ cell development, a crucial feature is the repression of transcription before spermatid elongation. Previously, we discovered that RNA-binding protein EWSR1 plays an important role in meiotic recombination and is highly expressed in late meiotic cells and post-meiotic cells. Here, we used a Ewsr1 pachytene stage-specific knockout mouse model to study its roles at late meiotic prophase I and in spermatozoa maturation. We show that loss of EWSR1 at this stage does not affect proper meiosis completion, but the developing germ cells exhibit defects in spermatid elongation and chromocenter formation. In the Ewsr1 conditional knockout testes, expression of many genes regulating spermatid differentiation is impaired, suggesting that EWSR1 may play important role in regulation of spermiogenesis related mRNA synthesis and spermatid differentiation. Overall design: RNA-seq of spermatocytes and round spermatids isolated by FACS sorting from Ewsr1 control and conditional knockout mice