Chapter 4-1 - Germline and Transgenerational Impacts of Toxicant Exposures

Abstract

Germ cells are responsible for the transfer of genetic information across generations. Much attention has recently been focused on the ability of environmental cues to also be inherited transgenerationally through the epigenome. In this chapter, we first describe the developmental odyssey that germ cells undergo during their differentiation and their ability to remodel their epigenome. We then review the evidence across various species providing support for the transgenerational inheritance of environmental exposures with a particular emphasis on recent mechanistic findings. In particular, recent findings have highlighted the ability for environmental cues, as varied as diet, temperature, or toxicants, to be transferred across generations through a variety of epigenetic mechanisms other than DNA methylation such as through various histone posttranslational modifications and through small RNAs. Together, the pieces of evidence presented here draw a compelling picture of the ability of organisms to integrate environmental signals for several generations.