Mouse EWSR1 is crucial for spermatid post-meiotic transcription and spermiogenesis

Abstract

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 the RNA-binding protein EWSR1 plays an important role in meiotic recombination in mouse, and showed that EWSR1 is highly expressed in late meiotic cells and post-meiotic cells. Here, we used an Ewsr1 pachytene stage-specific knockout mouse model to study the roles of Ewsr1 in late meiotic prophase I and in spermatozoa maturation. We show that loss of EWSR1 in late meiotic prophase I does not affect proper meiosis completion, but does result in defective spermatid elongation and chromocenter formation in the developing germ cells. As a result, male mice lacking EWSR1 after pachynema are sterile. We found that in Ewsr1 CKO round spermatids, transition from a meiotic gene-expression program to a post-meiotic and spermatid gene expression program related to DNA condensation is impaired, suggesting that EWSR1 plays an important role in regulation of spermiogenesis-related mRNA synthesis necessary for spermatid differentiation into mature sperm.

Deficiency of IQCH causes male infertility in humans and mice

“…5E), implicating this subset of genes as direct targets. Among the 76 proteins, 21 were RNA-binding proteins (RBPs), 10 of which were suggested to be involved in spermatogenesis (Kuroda et al 2000, Yang et al 2012, Chapman et al 2013, Fukuda et al 2013, Legrand et al 2019, Sechi et al 2019, Liang et al 2021, Tian and Petkov 2021, Wang et al 2022, Xu et al 2022); 8 were involved in mitochondrial function; and 4 were calcium channel activity-related proteins (Fig. 5F).…”

Gammaherpesvirus-mediated repression reveals EWSR1 to be a negative regulator of B cell responses

“…To determine whether the requirement for EWSR1 repression was intrinsic to B cell infection or instead due to effects on other cell types, we generated mice with B cell–specific deletion of EWSR1 . Mice homozygous for loxP-flanked (floxed) EWSR1 exon 4 (EWSR1 flox/flox CD19 +/+ ; designated EWSR1 WT mice) ( 32 , 33 ) were crossed with CD19-Cre mice ( 34 ) to generate CKO mice in which EWSR1 is specifically deleted in B cells (EWSR1 flox/flox CD19 Cre/+ ; designated EWSR1 CKO mice) ( Fig. 2 A ).…”

“…The mouse line C57BL/6N-Ewsr1 <tm1c(EUCOMM)Wtsi> /TcpPtKV contains conditional EWSR1 alleles through insertion of two loxP sites flanking exon 4 of the EWSR1 gene (designated EWSR1 flox/flox mice) ( 32 , 33 ). CD19-Cre mice [B6.129P2(C)- Cd19 tm1(cre)Cgn /J, 006785] ( 34 ) that express the Cre recombinase gene under the control of the CD19 promoter throughout B lymphocyte development were purchased from The Jackson Laboratory.…”

The RNA-binding protein FUS/TLS interacts with SPO11 and PRDM9 and localize at meiotic recombination hotspots

“…They contain several conserved domains: a serine-tyrosine-glycine-glutamine (SYGQ) domain embedded in the DNA activation domain (AD), 3 glycine-arginine (RGG) rich regions that affect RNA binding, one conserved RNA-binding domain (RBD, formed by an RNA-recognition motif, RRM), and a zinc finger domain that is also involved in nucleic acid binding [ 1 ]. Interestingly FET proteins are also expressed in testis, where, in addition to controlling transcription of post-meiotic genes [ 16 ], they play key functions in the early stages of meiosis, as demonstrated by massive germ cell apoptosis in spermatocytes carrying ablation of either Ewsr1 or Fus genes [ 17 , 18 ].…”