PgmNr P2066: The evolution of sexual dimorphism of recombination rate in house mice.

Authors:
April Peterson; Bret Payseur


Institutes
The University of Wisconsin-Madison, Madison, WI.


Abstract:

Although most studies of genetic diversity assume that the recombination rate is constant, this important parameter varies among individuals. Heterochiasmy, or - the sexual dimorphism in recombination rate - is one of the most striking forms of this variation. The theoretical foundation for recombination rate and heterochiasmy evolution is well established, yet these theoretical models remain largely untested due to a lack of empirical data. We aim to remedy this gap by expanding the range of empirical measurements and developing a framework for interpretation of observed patterns within an evolutionary context. Using an immunohistochemical approach that enables measurement in single oocytes and spermatocytes, we quantify variation across three wild-derived inbred strains of house mice (Mus musculus) in the genome-wide recombination rate, the synaptonemal complex length and the position of crossovers. We observe faster evolution in the genomic recombination rate of male house mice and divergence in the synaptonemal complex length across inbred strains. These data represent a subset of a larger panel of divergent inbred strains to be sampled across the murine phylogeny. When complete, these measures of heterochiasmy will enable us to test hypotheses for sex-specific evolution of genome-wide recombination rate.