Teleosts as Models for Epigenetic Inheritance

Teleost fish exhibit a striking divergence from mammals in how they regulate their epigenome. Unlike mammals, they do not undergo the extensive DNA methylation erasure and resetting events that occur during early embryogenesis, germline specification, and spermatogenesis. Consequently, DNA methylation patterns in teleosts might persist across generations, making these species potentially valuable models for studying intergenerational and transgenerational epigenetic inheritance. Recent findings suggest that environmental perturbations can induce heritable epigenetic changes in teleosts, raising the possibility that, in the absence of global epigenetic reprogramming, such changes could have long-lasting consequences. This review summarises current knowledge on DNA methylation stability and inheritance in teleosts, with a particular focus on the two teleost models, zebrafish and medaka. Moreover, the review discusses the ecological and evolutionary implications of epigenetic inheritance and highlights emerging experimental approaches for rigorously assessing transgenerational epigenetic effects in fish.