Meeting Abstract
P2.6 Monday, Jan. 5 Effects of polyploidy on female call preference in gray treefrogs, Hyla chrysoscelis. TUCKER, Mitch*; HUMFELD, Sarah C.; GERHARDT, H. Carl; University of Missouri, Columbia matkcc@mizzou.edu
The gray treefrog complex consists of two cryptic species; Hyla versicolor is a tetraploid (4N=48) species that arose from the polyploidization of its diploid counterpart, H. chrysoscelis (2N=24) and two other extinct treefrog species. Speciation via polyploidy is almost instantaneous because polyploid species are reproductively isolated from their non-polyploid ancestors. However, the establishment of new polyploid lineages requires assortative mating between polyploids. Genome duplication has been shown to affect the quality of the male’s species-specific mate-attraction signal (pulse repetition rate), thus polyploids could potentially be reproductively isolated from their diploid ancestors as a result of changes in the species communication system. We are investigating the influence of ploidy on female preferences for advertisement calls to determine whether polyploidization is a means by which senders and receivers in a communication system can evolve in tandem. To answer this question, we have created autopolyploid individuals and will test the acoustic mate-choice preferences of female polyploids upon reaching sexual maturity. The experimental tests compare preferences for call traits that vary between the two species, including call peak frequency, pulse shape, and pulse rate. We are also testing the hypothesis that changes in calls and preferences of polyploids are mediated through the influence of genome size on cellular and/or tissue dimensions by examining the behavior and cellular dimensions of H. chrysoscelis raised at different larval densities. We expect to find that polyploidy and cellular dimensions affect the advertisement-call preferences of female H. chrysoscelis treefrogs, independent of other factors. We will present preliminary results from these two sets of experiments including female preferences and effects of larval densities on cell dimensions.
