Female animals rely on information regarding numerous male traits when choosing a mate. Females may make mate choice decisions prior to copulation, or following copulation. If a female mates with multiple males, she may exhibit cryptic female choice, which is defined as the ability of a female to bias the fertilization success of certain males over others based on particular preferred traits. In some cases, females choose a mate based on his genetic make-up in order to acquire favorable genes for their offspring. This study will investigate the role of the major histocompatibility complex (MHC) in mate choice decisions by female guppies (Poecilia reticulata). The MHC is a set of genes involved in immunity; a female should choose a male with a more diverse MHC because her offspring will be equipped with a broader spectrum of tools with which to combat infection. Using both a behavioral and molecular approach, this study will test for cryptic female choice and whether female guppies use MHC diversity in males as a basis for mate choice. This integrative study will contribute to multiple scientific fields, including immunology, reproductive physiology, kin discrimination and behavioral ecology. In particular, the field of conservation biology will especially benefit from this study, especially as it relates to reproduction in other species. As survival for many endangered species depends on successful breeding, knowledge of reproductive processes following fertilization will be critical to engendering reproductive success. Finally, this study also incorporates an educational component. One female undergraduate student has already participated in the research, and plans are underway to incorporate additional undergraduates, as well as high school students. The PI and co-PI will integrate research and education by designing an Animal Behavior laboratory based on the proposed research when the PI teaches the course in fall 2007.
