BET bromodomain inhibitor JQ1 regulates spermatid development by changing chromatin conformation in mouse spermatogenesis

As a BET bromodomain inhibitor, JQ1 has been proven have efficacy against a number of different cancers. In terms of male reproduction, JQ1 may be used as a new type of contraceptive, since JQ1 treatment in male mice could lead to germ cell defects and a decrease of sperm motility, moreover, this effect is reversible. However, the mechanism of JQ1 acting on gene regulation in spermatogenesis remains unclear. Here, we performed single-cell RNA sequencing (scRNA-seq) on mouse testes treated with JQ1 or vehicle control to determine the transcriptional regulatory function of JQ1 in spermatogenesis at the single cell resolution. We confirmed that JQ1 treatment could increase the numbers of somatic cells and spermatocytes and decrease the numbers of spermatid cells. Gene Ontology (GO) analysis demonstrated that differentially expressed genes which were down-regulated after JQ1 injection were mainly enriched in “DNA conformation change” biological process in early developmental germ cells and “spermatid development” biological process in spermatid cells. ATAC-seq data further confirmed that JQ1 injection could change the open state of chromatin. In addition, JQ1 could change the numbers of accessible meiotic DNA double-stranded break sites and the types of transcription factor motif that functioned in pachytene spermatocytes and round spermatids. The multi-omics analysis revealed that JQ1 had the ability to regulate gene transcription by changing chromatin conformation in mouse spermatogenesis, which would potentiate the availability of JQ1 in male contraceptive.

The lncRNA MARS modulates the epigenetic reprogramming of the marneral cluster in response to ABA

Clustered organization of biosynthetic non-homologous genes is emerging as a characteristic feature of plant genomes.The co-regulation of clustered genes seems to largely depend on epigenetic reprogram-ming and three-dimensional chromatin conformation.In this study,we identified the long non-coding RNA(lncRNA)MARneral Silencing(MARS),localized inside the Arabidopsis marneral cluster,which con-trols the local epigenetic activation of its surrounding region in response to abscisic acid(ABA).MARS modulates the POLYCOMB REPRESSIVE COMPLEX 1(PRC1)component LIKE HETEROCHROMATIN PROTEIN 1(LHP1)binding throughout the cluster in a dose-dependent manner,determining H3K27me3 deposition and chromatin condensation.In response to ABA,MARS decoys LHP1 away from the cluster and promotes the formation of a chromatin loop bringing together the MARNERAL SYNTHASE 1(MRN1)locus and a distal ABA-responsive enhancer.The enrichment of co-regulated lncRNAs in clustered meta-bolic genes in Arabidopsis suggests that the acquisition of novel non-coding transcriptional units may constitute an additional regulatory layer driving the evolution of biosynthetic pathways.