Mammalian sperm nuclear organization: resiliencies and vulnerabilities.

A. Kocer,J. Torres-Carreira,J. R. Drevet,P. Gharagozloo,A. Champroux

doi:10.1186/s12610-016-0044-5

Abstract

Sperm cells are remarkably complex and highly specialized compared to somatic cells. Their function is to deliver to the oocyte the paternal genomic blueprint along with a pool of proteins and RNAs so a new generation can begin. Reproductive success, including optimal embryonic development and healthy offspring, greatly depends on the integrity of the sperm chromatin structure. It is now well documented that DNA damage in sperm is linked to reproductive failures both in natural and assisted conception (Assisted Reproductive Technologies [ART]). This manuscript reviews recent important findings concerning - the unusual organization of mammalian sperm chromatin and its impact on reproductive success when modified. This review is focused on sperm chromatin damage and their impact on embryonic development and transgenerational inheritance.

Highlights

In both female and male, the germline is the only heritable lineage that guarantees the continuity of life
chromatin immunoprecipitation (ChIP) studies utilizing histone antibodies to recover the histone-associated DNA sequences in mature sperm revealed histones to be significantly enriched at the promoters of: genes coding for microRNAs, genes involved in early embryonic development, genes subjected to genomic imprinting, and genes involved in spermatogenesis [99]
We have shown earlier that in mouse an epididymal luminal scavenger, the glutathione peroxidase 5 protein (Gpx5) is critical in this posttesticular disulfide bridging process since it contributes to fixing the optimal Hydrogen peroxide (H2O2) concentration in the epididymal fluid [145]

Summary

Introduction

In both female and male, the germline is the only heritable lineage that guarantees the continuity of life. One of the hallmarks of spermiogenesis is the replacement of nuclear somatic-like histones by protamines (small basic proteins) facilitating compaction of the sperm nucleus and, of the sperm head. Chromatin organization and all its associated modifications, whether it concerns the DNA itself and/or the nuclear histones, are critical for gene expression, cell division, and differentiation [5, 6].

Results

Conclusion