SGER: Effects of Interpopulation Hybridization on DNA Methylation

University Of Southern California, Los Angeles CA

Investigators

Abstract

This project investigates the possibility that changes in DNA methylation play a role in the early stages of speciation. In the process of screening amplified fragment length polymorphisms (AFLPs) in the copepod Tigriopus californicus, particular regions of DNA were found to be methylated in one population but not in another. Further, hybridization between populations appeared to induce changes in methylation. This SGER seeks to more definitively test for methylation differences between parentals and hybrids by using methylation-sensitive AFLP to screen a large number of loci in a much wider cross than was used in the past. Because the distribution of methylated DNA throughout the genome is poorly known in invertebrates and wholly unknown in this particular species, a locus-specific technique will be used to assay methylation at selected microsatellite, ribosomal DNA and protein-coding loci. Such work has medical implications due to the role of DNA methylation in processes ranging from transcription regulation to spontaneous mutation to carcinogenesis. If hybridization-induced changes in methylation are confirmed, this has considerable implications for conservation and management practices aimed at promoting intermixing between populations. Both undergraduate and graduate students will participate in the project and learn a variety of techniques in molecular and evolutionary genetics.