Non-Genetic Inheritance, Fertility and Assisted Reproductive Technologies

The concept of non-genetic inheritance is gaining considerable attention in the assisted reproductive technology (ART) community due to the reported differences between children born from ART and those that are conceived naturally. It has been demonstrated that children conceived via ART have differences in fetal growth, birth weight, congenital abnormalities, cardiometabolic parameters, glucose homeostasis as well as changes to body composition compared to children conceived naturally. Although these changes may have a parental contribution and may be influenced by the pathology of infertility there is concern that the technologies themselves may play a role. In support of this, is emerging evidence that aspects of ART technology such as culture media formulation and insemination method can alter offspring phenotype. In addition it is also documented that exposure to environmental factors, such as toxins can impact on offspring gametogenesis such that these perturbations persist through generations. With the increasing use of ART and the development of new technologies it is vital that we understand whether ART can effect non-genetic inheritance so that we can optimise technology and prevent abnormal programming and its impact on all aspects of offspring health including fertility and a possible transmission to subsequent generations.

Non-genetic inheritance in evolutionary theory - the importance of plant studies

Emerging evidence points to a causal role for epigenetic variation in evolution, but evolutionary biologists have been reluctant to incorporate epigenetics into modern evolutionary theory. Part of this ambivalence comes from the assumption that epigenetic inheritance is only relevant to the evolution of plants, which is perpetuated by a comparative lack of evolutionary studies in animals. However, although most of the evidence for epigenetic inheritance comes from plants, plants and animals share many homologous epigenetic mechanisms, and plants provide a more tractable system for investigating the causal role of epigenetic mechanisms underlying phenotypic variation and its relationship with fitness. The insights from studies of epigenetic inheritance in plants may be applicable across a broad range of taxa once we establish commonalities and differences in epigenetic machinery. In this paper we present evidence for a role of epigenetic mechanisms in the evolutionary process and discuss common objections to incorporating epigenetics into evolutionary theory. This review is not exhaustive, but is meant to demonstrate that epigenetic inheritance can be incorporated into current evolutionary theory without overhauling its foundations.

Do Fathers Matter: Influencing Neural Phenotypes Through Non-Genetic Transmission of Paternal Experiences?

Understanding the role of fathers and how paternal experiences actually influence offspring outcomes is a rapidly growing field of research. This Lamarkian mode of inheritance offers offspring an additional mechanism for environmental adaptation that can occur in a single generation, rather than waiting for chance mutations in DNA that may or may not increase an individual’s chances for survival. This review article examines the influences of many paternal experiences including, stress, drugs, and alcohol, along with enrichment, exercise, diet and paternal age, on offspring neural phenotypes. Where possible, there is also discussion of the underlying mechanisms that facilitate the transmission of these experiences to the offspring. Although previous ideologies maintained a small role for fathers (merely as sperm-donors) in the developmental trajectories of the offspring they sired, research now demonstrates that they influence a wide range of outcomes such as drug and alcohol tolerance, susceptibility to mental illness, and patterning of the hypothalamicpituitary- adrenal (HPA) stress response. These novel findings emphasize the complexity and extensive realm of factors that can influence the development of offspring neural phenotypes.