Meeting Abstract
S1.3-1 Saturday, Jan. 4 13:30 Epigenetics and Species Divergence KELLER, TE; ZENG, J; MENDIZABAL, I; YI, SV*; Georgia Institute of Technology soojinyi@gatech.edu
An important aspect of epigenetic inheritance is its pliability in response to changing signals from cellular environments. As such epigenetic modifications exhibit developmental- and cell type specific patterns that may underlie differentiation as well as phenotypic plasticity. Recently, however, a new aspect of epigenetic modification has emerged. Namely, epigenetic patterns also appear to be species-specific, and often exhibit remarkable degrees of conservation across long evolutionary timescales. In this talk we will discuss multiple examples of epigenetic modifications that originated in the distant past and have persisted in a conserved fashion to the present day. As a potential mechanism underlying such conservation, we will also discuss the impact of single nucleotide substitutions and other genetic factors in determining population-specific or species-specific patterns of DNA methylation and histone modifications. In turn, evolutionary dynamics of epigenetic modifications may drive important species-specific features. A particular example is that of the human brain. The Human brain represents an exceptionally rapid and dramatic functional innovation. Comparative studies of DNA methylation and histone modification between human and chimpanzee brains have identified hundreds of loci that exhibit differential levels of DNA methylation. These loci mark those genes associated with cognitive abilities, as well as human-specific neuropsychiatric diseases. Finally, fine-scale recombination rates, which are fundamental aspects of genome variation, appear to co-vary with species-specific patterns of epigenetic modifications. These studies highlight the significant role of epigenetic modifications in species divergence at both short and long evolutionary timescales. Thus epigenetic modifications may provide complementary aspect of evolution in addition to genomic and other functional studies.
