CFP1 safeguards male meiotic progression by regulating meiotic gene expression
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ABSTRACT: Meiosis occurs specifically in germ cells to produce sperm and oocytes that are competent for sexual reproduction. Multiple factors are required for successful meiotic entry, progression, and termination. Trimethylation of histone H3 on lysine 4 (H3K4me3), a mark of active transcription, has been implicated in spermatogenesis by forming double strand breaks (DSBs). The role of H3K4me in transcriptional regulation during meiosis however, remains poorly understood. Here, we reveal that mouse CXXC finger protein 1 (Cfp1), a component of H3K4me methyltransferases Setd1a/b, is dynamically expressed in differentiating male germ cells and safeguards meiosis by controlling gene expression. Depletion of Cfp1 in male germ cells resulted in infertility with reduced H3K4me3, spermatogenic arrest, and repression of essential germ cell development and meiosis genes. Importantly, ChIP-Seq analysis revealed that Cfp1 is mainly enriched at transcriptional start sites to promote gene expression and H3K4me2/3 levels at pachytene stage. The most highly enriched genes were associated with meiosis and homologous recombination during differentiation of spermatocytes to round spermatids. Additionally, missense mutations of human CFP1 were prevalent in patients with nonobstructive azoospermia. Therefore, our study establishes a mechanistic link between CFP1-mediated transcriptional control and meiotic progression, and provides unprecedented genetic basis for understanding human sterility.
Project description:CXXC finger protein 1 (Cfp1) is a DNA-binding component of the SETD1 methyltransferase complex, targets SETD1A/B to most CpG islands (CpGI), and mediates the generation of H3K4me3. Deficiency of CFP1 in mice leads to pre-implantation lethality. Previous data suggest an indispensable role of CFP1 in germ cell development and meiosis. However, it remains unclear if CFP1-mediated H3K4 trimethylation is also required for the earliest stages of meiosis in both male and female germ cells. Here, we revealed that Cxxc1 deletion caused a decrease of H3K4me3 levels in spermatocytes after the zygotene stage, impaired double strand breaks (DSBs) repairing, and crossover formation in meiotic prophase. As the results, Cxxc1-deleted spermatocytes failed to complete meiosis and were arrested at the meiosis II. ChIP-seq results revealed that H3K4me3 globally descreased at transcriptional start sites in Cxxc1-null spermatocytes at the leptotene/zygotene and pathytene stages.RNA-seq at different stages revealed an earlier expression of genes within the spermatogenesis pathway in Cxxc1-null spermatocytes. These results indicated that CFP1 is required for H3K4me3 accumulation at the gene promoters of male germ cells and play a key role in regulating programed gene expression that is essential for spermatogenesis.
Project description:Spermatogenesis is a complex process involving meiosis in spermatocytes and dynamic epigenetic changes that ensure the inheritance of genetic traits. CXXC finger protein 1 (Cfp1), a component of the SETD1 methyltransferase complex, has a binding domain specific for unmethylated CpG sites. Previous studies have implicated Cfp1 in the epigenetic changes required for meiosis in spermatocytes, and its loss of function has been shown to result in male sterility. In this study, we aimed to gain a comprehensive understanding of Cfp1 function in spermatocytes by examining its genome-wide binding profile and the resulting changes in DNA methylation and H3K4me3, a histone modification associated with active gene transcription. We isolated Cfp1-depleted spermatocytes and performed H3K4me3 ChIP-seq and reduced-representation bisulfite sequencing (RRBS) analyses. By integrating these multi-omics datasets with Cfp1 ChIP-seq analysis, we identified genes directly regulated by Cfp1 and characterised the epigenetic changes associated with its regulation. Our analysis shows that Cfp1 not only directly affects the regulation of genes essential for meiosis, but also has a significant impact on the overall regulation of gene expression. The knowledge gained from studying the regulatory mechanisms of Cfp1 in spermatocytes provides valuable information about the reproductive process and contributes to our understanding of the underlying causes of infertility.
Project description:As Setd1a is a methyltransferase targeting H3K4, we performed H3K4Me3 ChIP in control and Setd1a KO cell to observe the effects of Setd1a on H3K4Me3. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for H3K4Me in control mouse UPS and Setd1a KO mouse UPS cells .
Project description:Male germ cells establish a unique heterochromatin domain, the XY-body, early in meiosis. How this domain is maintained through the end of meiosis and into post-meiotic germ cell differentiation is poorly understood. ADAD2 is a late meiotic male germ cell specific RNA binding protein, loss of which leads to post-meiotic germ cell defects. Analysis of ribosome association in Adad2 mutants revealed defective translation of Mdc1, a key regulator of XY-body formation, late in meiosis. As a result, Adad2 mutants show normal establishment but failed maintenance of the XY-body. Observed XY-body defects are concurrent with abnormal autosomal heterochromatin and ultimately lead to severely perturbed post-meiotic germ cell heterochromatin and cell death. These findings highlight the requirement of ADAD2 for Mdc1 translation, the role of MDC1 in maintaining meiotic male germ cell heterochromatin, and the importance of late meiotic heterochromatin for normal post-meiotic germ cell differentiation.
Project description:Trimethylation of histone H3 lysine 4 (H3K4me3) is a mark of active and poised promoters. The Set1 complex is responsible for most somatic H3K4me3 and contains the conserved subunit Cfp1, which binds to unmethylated CpGs and links H3K4me3 with CpG islands (CGIs). Here we report that Cfp1 plays unanticipated roles in organising genome wide H3K4me3 in embryonic stem cells. Cfp1-deficiency caused two contrasting phenotypes: drastic loss of H3K4me3 at expressed CGI-associated genes, with minimal consequences for transcription, and creation of ectopic H3K4me3 peaks at numerous regulatory regions. DNA binding by Cfp1 was dispensable for targeting H3K4me3 to active genes, but was required to prevent ectopic H3K4me3 peaks. We analysed gene expression in wild-type, Cfp1-/-, Cfp1wt rescue and Cfp1C169A rescue ES cells on the MouseWG-6 v2.0 Expression BeadChip (Illumina). We found that the presence of ectopic peaks at enhancers often coincided with increased expression of nearby genes. This suggests that CpG targeting prevents leakage of H3K4me3 to inappropriate chromatin compartments. Our results demonstrate that Cfp1 is a specificity factor that integrates multiple signals, including promoter CpG content and gene activity, to regulate genome-wide patterns of H3K4me3.
Project description:Meiosis is a key step during germ cell differentiation, accompanied by the activation of thousands of genes through germline-specific chromatin reorganization. The chromatin remodeling mechanisms underpinning early meiotic stages remain poorly understood. Here we focus on the function of one of the major autism genes, CHD8, in spermatogenesis, based on the epidemiological association between autism and low fertility rates. Specific ablation of Chd8 in germ cells results in gradual depletion of undifferentiated spermatogonia as well as failure of meiotic double strand formation followed by arrest at meiotic prophase I and cell death. Transcriptional analyses demonstrate that CHD8 is required for extensive activation of spermatogenic genes in spermatogonia, necessary for spermatogonial proliferation and meiosis. CHD8 directly binds to promoters of genes crucial for meiosis, including H3K4me3 histone methyltransferase genes, meiotic cohesin genes, HORMA domain containing genes, synaptonemal complex genes, and DNA damage response genes. Through transcriptionally regulating the interaction of these meiosis-related genes, we argue that CHD8 contributes to meiotic double strand break formation and subsequent meiotic progression. Our study uncovers an essential role of CHD8 for the proliferation of undifferentiated spermatogonia and the successful progression of meiotic prophase I.
Project description:The meiosis-specific chromosomal events of homolog pairing, synapsis, and recombination occur over an extended meiotic prophase I. In this study, we show that, in mice, maintenance of an extended meiotic prophase I requires the gene Meioc, a germ-cell specific factor conserved in most metazoans. Using immunoprecipitation and quantitative mass spectrometry, we identify proteins that interact with MEIOC in the mouse germ line.
Project description:We report the application of single molecule-based sequencing technology for high-throughput mapping of CFP1, RNA polymerase II and H3K4me3 in mouse brain. By obtaining sequence from chromatin immunoprecipitated DNA, we generated genome-wide binding / chromatin-state maps for mouse brain. We find a good correlation between CFP1 binding and H3K4me3 consistent with it presence in the SetD1 histone methylatransferase complex. Mapped RNA polymerase II colocalised with the majority of CFP1 / H3K4me3 positive CpG islands but not all. This study provides a comprehensive characterisation of the genome wide distribution of a previously uncharacaterised DNA binding factor and suggests a link between DNA base composition and chromatin state. Examination of H3K4me3, RNA PolymeraseII and CFP1 in mouse brain.