By Institute of Science in Society
The first hint that fathers can pass on acquired characters was the discovery that the experience of young boys could affect not just their health in later life, but also the health of their sons and grandsons. That was the beginning of the epigenetic revolution [1] (Epigenetic Inheritance – What Genes Remember, SiS 41). All kinds of life experiences, good and bad, from caring mothers to environmental toxins, leave epigenetic imprints that are passed on for generations afterwards (see [2, 3] Caring Mothers Strike Fatal Blow against Genetic Determinism, and Epigenetic Toxicology, SiS 41). In the case of environmental toxins, Michael Skinner’s reproductive biology lab at Washington State University Pullman in the United States first reported in 2005 that injecting pregnant rats with endocrine disruptor fungicide vinclozolin caused sperm abnormalities that persisted in the male progeny for at least 4 generations [4]. The effects on reproduction correlate with altered DNA methylation pattern in the germ line (though the methylation differences vary widely among the animals, and failed to satisfy his critics [5]). Subsequently, they found that insecticides DDT and permethrin, jet fuel, plastic additives phthalates and bisphenol A, and dioxin can all trigger trans-generational health effects in rats such as obesity and ovarian disease, and each resulted in a different pattern of methylation in sperm DNA, according to Skinner.
DNA methylation is not the only means of transmitting acquired epigenetic information to subsequent generations, chromatin modification (via histone and RNA) as well as various non-coding (nc) RNAs are also involved (reviewed in [6]). NcRNAs such as those involved in RNA interference can be independently inherited, and can also direct chromatin modification and DNA methylation see [7, 8] RNA Inheritance of Acquired Characters, and Nucleic Acid Invaders from Food Confirmed, SiS 63).
