Roles of Epigenetic Modifications in Male Reproductive Toxicity

Abstract

Spermatogenesis is a highly specialized process resulting in the formation of functional spermatozoa for male reproduction and consists of the mitotic division of spermatogonia, meiosis of spermatocytes, and a metamorphic change (spermiogenesis). Spermatogenesis requires specialized epigenetic regulation to generate functional spermatozoa. During mitotic proliferation and meiosis of spermatogonia and spermatocytes, respectively, and the metamorphic changes of spermiogenesis, epigenetic modifications including DNA methylation, histone modifications and RNA modifications are essential. Of particular note, N6-methyladenosine (m6A) modifications of RNA emerge as crucial epigenetic changes for spermatogenesis. After fertilization, decondensation of the male pronucleus is accompanied by epigenetic reprogramming. Exposure to environmental toxicants can impair male reproduction by altering gene expression and epigenetic profiles, compromising fertility and offspring health. This chapter presents a systematic review of the role of environmental pollution-induced epigenetic alterations in male reproductive toxicity. Elucidating the links between environmental toxicants, epigenetic disruption of spermatogenesis, and impaired male fertility or offspring health is crucial to understand and address this public health issue.