DISSERTATION RESEARCH: Polyandry in Crickets: Disentangling the Genetic Benefits

Board Of Trustees Of Illinois State University, Normal IL

Investigators

Abstract

Abstract of Proposed Research Project Title: Dissertation Research: Polyandry in crickets: disentangling the genetic benefits Principal Investigator: Scott Kitchener Sakaluk Co-Principle Investigator: Tracie Marie Ivy Although mating is often costly, females of many species mate multiple times and with multiple partners, presumably because females accrue benefits that outweigh the costs. Material benefits, such as courtship food gifts, directly increase a female's reproductive success, while genetic benefits indirectly improve a female's success through the performance of her offspring. Recent work involving decorated crickets indicates that females mating multiply produce significantly more surviving offspring than those mating only once, particularly when females mate with multiple partners. Moreover, the data suggest that the increase in offspring survival is due to genetic rather than material benefits. The object of the proposed research is to test two hypotheses regarding the nature of genetic benefits obtained via promiscuous mating in decorated crickets: 1) offspring viability (or sexual attractiveness) is enhanced through paternally-derived genes and 2) females mating with multiple partners increase the probability that their eggs will be fertilized by males with whom they are genetically compatible. These hypotheses will be tested by utilizing a design used frequently in agricultural research, the full diallel cross, which involves all possible crosses among a set of inbred parental lines. If promiscuous mating results in offspring inheriting genes from high-quality males, I predict that females will derive higher fitness by mating with certain males, irrespective of the genetic background of the female. However, if genetic compatibility is most important, I predict that female fitness will be determined by the interaction between paternal and maternal genes. Knowing which of these genetic mechanisms drives female mating preferences is critical to understanding the evolution of animal mating systems.