Epigenetics in male reproduction: effect of paternal diet on sperm quality and offspring health

Abstract

Epigenetic inheritance and its underlying molecular mechanisms are among the most intriguing areas of current biological and medical research. To date, studies have shown that both female and male germline development follow distinct paths of epigenetic events and both oocyte and sperm possess their own unique epigenomes. Fertilizing male and female germ cells deliver not only their haploid genomes but also their epigenomes, which contain the code for preimplantation and postimplantation reprogramming and embryonal development. For example, in spermatozoa, DNA methylation profile, DNA-associated proteins, protamine 1:protamine 2 ratio, nucleosome distribution pattern, histone modifications and other properties make up a unique epigenetic landscape. However, epigenetic factors and mechanisms possess certain plasticity and are affected by environmental conditions. Paternal and maternal lifestyle, including physical activity, nutrition and exposure to hazardous substances, can alter the epigenome and, moreover, can affect the health of their children. In male reproductive health, data are emerging on epigenetically mediated effects of a man's diet on sperm quality, for example through phytochemicals, minerals and vitamins, and nutritional support for subfertile men is already being used. In addition, studies in animal models and human epidemiological data point toward a transgenerational effect of the paternally contributed sperm epigenome on offspring health.

Obesity, a serious etiologic factor for male subfertility in modern society

“…For instance, epidemiologic evidences showed that environmental challenges imposed on the father, such as stress, specific diets, toxins, tobacco smoking and alcohol consumption, have been found to influence the development of the offspring via the non-genetic alterations within sperm including small non-coding RNAs, DNA damage, DNA methylation and histone modifications (Chen et al 2016b, Rando 2016, Schagdarsurengin & Steger 2016, Fullston et al 2017.…”

Effect of Nano-SiO2 on Expression and Aberrant Methylation of Imprinted Genes in Lung and Testis

“…These reproductive toxicities observed in C. elegans included reduced brood size, fertilized egg, and spermatide activation [6]. There is growing evidence that certain environmental effects can be passed to offspring via paternally pathways without changes in the sperm genome [7, 8]. Paternal information exists not only in the genome, but also in related specific epigenetic markers, mRNA content, and non-coding RNA.…”

Transgenerational paternal transmission of acquired traits: stress-induced modification of the sperm regulatory transcriptome and offspring phenotypes

“…Such information could eventually be used to tailor personalised medicine approaches, based on relative genetic and epigenetic contributions to disease predisposition. For example, we know that diet directly impacts on sperm quality and influences the reproductive health of offspring [61]. This kind of ‘sperm epi-genotype’ data could not only inform public health messages targeted at males planning parenthood, but also help identify the potential causes (and thus therapeutic options) of medical conditions which occur in later generations.…”