Abstract
In the last 40 years, male reproductive health—which is very sensitive to both environmental exposure and metabolic status—has deteriorated and the poor sperm quality observed has been suggested to affect offspring development and its health in adult life. In this scenario, evidence now suggests that epigenetics shapes endocrine functions, linking genetics and environment. During fertilization, spermatozoa share with the oocyte their epigenome, along with their haploid genome, in order to orchestrate embryo development. The epigenetic signature of spermatozoa is the result of a dynamic modulation of the epigenetic marks occurring, firstly, in the testis—during germ cell progression—then, along the epididymis, where spermatozoa still receive molecules, conveyed by epididymosomes. Paternal lifestyle, including nutrition and exposure to hazardous substances, alters the phenotype of the next generations, through the remodeling of a sperm epigenetic blueprint that dynamically reacts to a wide range of environmental and lifestyle stressors. With that in mind, this review will summarize and discuss insights into germline epigenetic plasticity caused by environmental stimuli and diet and how spermatozoa may be carriers of induced epimutations across generations through a mechanism known as paternal transgenerational epigenetic inheritance.
Highlights
An Overview of Epigenetic MechanismsMale infertility is one of the most common reproductive disorders strongly driven by environmental conditions before conception [1]
Different epigenetic mechanisms—DNA methylation, histone modifications, non-coding RNA (ncRNA)—are interconnected and form an “epigenetic network” that plays a key role in the proper function of cells, male gamete included
Epigenetic signature starts to be defined in the testis, during germ cell progression, to reach the highest degree of complexity in SPZ
Summary
Male infertility is one of the most common reproductive disorders strongly driven by environmental conditions before conception [1]. The most commonly studied epigenetic mechanisms are the following: DNA methylation, histone modifications, chromatin folding and non-coding RNA expression. Chromatin structure shows a high degree of plasticity, tightly controlled by a large number of possible HPTMs. Interestingly, a crosstalk between different modifications exists, adding an extra level of complexity in gene expression regulation [14]. A crosstalk between different modifications exists, adding an extra level of complexity in gene expression regulation [14] It is well-established that only a small subset of the human genome (1–2%) includes protein-coding sequences, while the remaining is constituted by regulatory DNA sequences transcribed into an unexpected variety of non-coding RNA (ncRNA) molecules, introns, transposons, repeats and other sequences whose function is yet far from being completely determined [15]. More complicated than first thought since it results from multiple epigenetic mechanisms, and by their interactions
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call