Genomics, epigenomics, differential gene expression and evolution of reproductive barriers among hybridizing Pitcairnia ssp. (Bromeliaceae)

Abstract

Species are isolated by a diversity of reproductive barriers that act either before or after fertilization, also called prezygotic or postzygotic reproductive isolation. Studies on epigenetic variation as a mechanism producing barriers to reproduction and speciation are now emerging. Such studies revealed that the role of DNA methylation in gene expression may also contribute to reproductive isolation barriers in plants and animals. In this project we aim to investigate the association between differential gene expression and variation of DNA methylation in the evolution of reproductive isolation and assortative mating during diversification and maintenance of Pitcairnia species (Bromeliaceae). For that, we will investigate the epigenomic patterns of sympatric and allopatric populations and hybrids between P. staminea and P. albiflos species; and understand the role of DNA methylation in gene expression of reproductive isolation between P. staminea and P. albiflos. Genomic DNA and total RNA will be extracted from the same sample using specific protocols. We will use a reduced-representation bisulfite sequencing, a high-resolution method for quantification of DNA methylation (bsRADseq) to obtain genome wide patterns of DNA methylations of P. staminea and P. albiflos and their hybrids. Further we will test the association between differential gene expression and differentially methylated regions of this species and hybrids. This project will shed light on the role of nongenetic inheritance, and its potential importance in population divergence and speciation. (AU)