Poster 32
Presenter: John Hvala
Thursday, 4:00 – 6:00pm
John A. Hvala and Bret A. Payseur Laboratory of Genetics, University of Wisconsin-Madison
Studying genomic variation in natural populations has great potential for revealing the genetic bases of complex traits. However, despite the progress made so far our understanding of how multiple evolutionary forces shape variation among genomes is still lacking. We are integrating population genomic simulations and analyses of genomic data from a hybrid zone between two nascent species of mice (Mus musculus musculus and M. m. domesticus) to identify deleterious epistatic interactions (Dobzhansky-Muller Incompatibilities) that block gene flow between species. The simulation engine models haplotypes as tracts of ancestry (identity-by-descent) and tracks junctions (recombination events between ancestry states in the genome). This allows us to quickly and efficiently simulate the evolution of entire genomes at arbitrarily fine resolutions. Furthermore, the simulation engine incorporates selection, drift, migration, and recombination allowing us to examine how each of these forces shapes haplotype variation during population admixture. We present results from these simulations that show detectable signatures in the frequency of junctions in genomic regions that harbor alleles under different selection regimes. These results show that junction frequencies have potential use in genomic scans for selection that, notably, can detect epistatic interactions. Thus, junctions may be useful for mapping Dobzhansky-Muller incompatibilities between species and detecting epistatic interactions in admixing populations. Similarly, junction based analyses may be useful in detecting epistasis in the mouse collaborative cross.