Epigenetics in Sperm, Epigenetic Diagnostics, and Transgenerational Inheritance

Abstract

Sperm are highly specialized cells transmitting the paternal genome to the oocyte and thus, to the next generation. For many years, it was believed that sperm was only contributing its DNA and nothing else. A growing body of evidence now supports the importance and relevance of the sperm epigenome for male fertility and offspring health. Sperm DNA methylation, histone alterations, and non-coding RNA are all involved and contribute to observable epigenetic alterations inherited by subsequent generations. Moreover, sperm has been shown to be particularly sensitive to different environmental exposures which can subsequently affect embryonic development and offspring health. Several studies have observed that such environmental insults cause changes in the sperm epigenome which can be passed to subsequent generations transgenerationally. Recent data suggest that the different sperm epigenetic alterations (DNA methylation, ncRNA, histone modifications, and retention) offer predictive diagnostic tools in the assessment of male infertility and potential impacts on subsequent generation disease etiology. This chapter will focus on the different epigenetic factors, epigenetic diagnostics, concept of transgenerational inheritance, and the potential use of epigenetics in the context of male infertility.