BRD4 dynamics reveal novel acrosome-dependent chromatin reorganization during post-meiotic mammalian sperm development

During the post-meiotic phase of spermatogenesis, transcription is progressively repressed as the nuclei of haploid spermatids are compacted through a dramatic chromatin reorganization involving hyper-acetylation and replacement of most histones with sperm-specific protamines. Although BRDT has been shown to function in transcription as well as histone removal in post-meiotic spermatids, it is unknown whether other BET family proteins play a role. Immunofluorescence of mouse testes revealed BRD4 in a complete ring around the nuclei of spermatids containing hyper-acetylated histones. The BRD4 ring lies directly adjacent to the acroplaxome, or the cytoskeletal base of the acrosome, and does not form in acrosomal mutant mice. ChIP sequencing in round spermatids revealed enrichment of BRD4 and acetylated histone H3 and H4 at the promoters of active genes. GO Term analysis showed that BRD4 and BRDT bind to distinct subsets of spermatogenesis-specific genes. Association of BRD4 with Cyclin T1 decreases as spermatogenesis progresses despite a persistence of association with acetylated H4. Moreover, acetylated histones are removed from the condensing spermatid nucleus in a wave following the progressing acrosome. These data provide evidence for an interesting mechanism in which BRD4 and perhaps acetylated histones are removed from the spermatid genome via the progressing acrosome as transcription is repressed.

Dataset features

Information

Specifications

Application:	ChIP-seq analysis
Number of samples:	9
Release date:	Mar 6 2015
Last update date:	Oct 24 2018
Access:	Public
Dataset link	BRD4 dynamics reveal novel acrosome-dependent chromatin reorganization during post-meiotic mammalian sperm development

Experimental Protocol

Single replicates each of Brd4, H3K9me3, H3K9ac, H4K5ac, H4K8ac, H4K12ac, H4K16ac, H4Kac (pan-acetyl antibody), and input in mouse round spermatid cells; input is used to control for local sonication efficiency bias.

Repositories

GEO

ArrayExpress

ENA

BioProject

Dataset features

Specifications

Experimental Protocol

Repositories

Download