DAZL mediates a broad translational program regulating expansion and differentiation of spermatogonial progenitors

Abstract

Fertility across metazoa requires the germline-specific DAZ family of RNA-binding proteins.Here we examine whether DAZL directly regulates progenitor spermatogonia using a conditional genetic mouse model and in vivo biochemical approaches combined with chemical synchronization of spermatogenesis. We find that the absence of Dazl impairs both expansion 5 and differentiation of the spermatogonial progenitor population. In undifferentiated spermatogonia, DAZL binds the 3' UTRs of ~2,500 protein-coding genes. Some targets are known regulators of spermatogonial proliferation and differentiation while others are broadly expressed, dosage-sensitive factors that control transcription and RNA metabolism. DAZL binds 3' UTR sites conserved across vertebrates at a UGUU(U/A) motif. By assessing ribosome 10 occupancy in undifferentiated spermatogonia, we find that DAZL increases translation of its targets. In total, DAZL orchestrates a broad translational program that amplifies protein levels of key spermatogonial and gene regulatory factors to promote the expansion and differentiation of progenitor spermatogonia.2

A regulatory role for CHD4 in maintenance of the spermatogonial stem cell pool

“…Unique DEGs were, however, identified in each cluster, including 117 DEGs in the SSC population that were not identified elsewhere ( Data S2 ; Figure 4 C). This included the RNA-binding protein DAZL, which is thought to drive spermatogonial differentiation ( Mikedis et al., 2020 ; Schrans-Stassen et al., 2001 ), and was significantly upregulated following Chd4 knockdown (p < 0.001) ( Data S2 ). Upon mining a publicly available anti-CHD4 chromatin immunoprecipitation (ChIP) dataset produced using THY1+ undifferentiated spermatogonia ( de Castro et al., 2020 ), it was determined that 102 of the DEGs identified here are direct targets of CHD4 binding ( Data S4 ), including Dmrt1 and Gfra1 ( Figure 4 B), which are known regulators of SSC function.…”

Novel Gene Regulation in Normal and Abnormal Spermatogenesis

“…Trim28 (tripartite motif-containing 28) promotes the differentiation of mouse SSCs [ 38 ], while specific deletion of TRIM71 results in the reduced number of undifferentiated spermatogonia and hinders the transition to differentiated state [ 39 ]. DAZL deficiency compromises the expansionand differentiation of spermatogonial progenitor cells by mediating extensive translation programs [ 40 ]. In the absence of Pramef12 , the number of mouse SSCs is decreased, and low expression of SSC maintenance-related genes and a defective ability of differentiation are observed [ 41 ].…”

A genome-wide knock-out screen for actors of epigenetic silencing reveals new regulators of germline genes and 2-cell like cell state

“…In serum condition, Dazl is repressed by two mechanisms: DNA methylation (Borgel et al, 2010;Hackett et al, 2012) and ncPRC1.6 (Endoh et al, 2017;Stielow et al, 2018); inactivation of either pathway causes its reactivation (Figure 1B). Dazl encodes an RNA-binding protein which is critical during gametogenesis (Zagore et al, 2018;Mikedis et al, 2020;Sharma et al, 2021), but it is also expressed during other developmental events, such as the 2-cell-stage (Rodriguez-Terrones et al, 2018) (Figure 1C). We verified by WGBS, RNA-seq, and RT-qPCR that the Dazl promoter was unmethylated and the gene expressed in 2i, whereas the Dazl promoter was methylated and the gene repressed in serum condition in our cellular background, J1 mouse ESC (Figure 1D-E).…”