Dr. Shawn Nordell
Mary Agnew
National Science Foundation Dissertation Improvement Grant
The role of the MHC in pre- and postcopulatory mate choice decisions by female guppies.
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.
Keefe Reuther
Dr. Shawn Nordell
National Science Foundation Dissertation Improvement Grant
Early Invasion Dynamics of the Japanese pavement ant, Tetramorium tsushimae in St. Louis, MO: The Genetic Structure of a Biological Invasion
The Japanese pavement ant, Tetramorium tsushimae, is a recently discovered invasive species found throughout the St. Louis Metropolitan area. Since the invasion was first identified, the species has rapidly spread and may have significantly reduced biodiversity. The primary goal of this research is to use this species to understand how recent biological invasions succeed by using methods in genetics, ecology, behavior, and computer modeling. Specifically, this funding will permit the researcher to use genes and biochemicals to test how this species has dispersed over time and how it aggressively competes with and kills other species.
Invasive species are non-native species that undergo rapid population growth and incur significant environmental and/or economic costs. Invasive species are the second leading cause of extinctions and population declines worldwide. Aside from their adverse effects on biodiversity, the negative effects of invasive species in the U.S. cost $137 billion annually. A major push in the study of biological invasions has been to understand the early stages of invasions, because once thoroughly established they are nearly impossible to eradicate. The Japanese pavement ant represents the most recently documented ant invasion in North America; as such, this system presents an indispensable opportunity to understand how early invasions succeed and spread. This research will provide valuable information for conservation efforts designed to prevent invasions and exacting such a large toll on the environment, biodiversity, and society.
Casey Dillman
Dr. Robert Wood
National Science Foundation Dissertation Improvement Grant
Systematics and Evolution of the Crayfish Genus Cambarus
Crayfishes form an integral part of freshwater ecosystems throughout eastern North America. Despite their importance, they have received little systematic attention compared to other groups of aquatic organisms. This study proposes to complete a phylogenetic (evolutionary) hypothesis for the second most species-rich genus of crayfishes in North America: Cambarus. The completed project will consist of three genomic data sets, a morphological character matrix and a phylogeny for these taxa. The resultant hypothesis will be used to investigate patterns of speciation, biogeography, and life-history evolution.
The proposed research includes training co-PI Dillman as a crayfish systematist, exposing undergraduate students to molecular laboratory techniques and phylogenetic methodology, and providing undergraduate students with a greater appreciation for biodiversity within this understudied group of organisms. The gene regions to be used are the most frequently used genes in systematic studies of North American crayfishes to date. This increases compatibility of the data to be generated with data previously published. Given the long-standing interest of P.I. Wood in biogeographic patterns in aquatic organisms (primarily fishes) the use of crayfishes broadens the scope of work in his lab and enhances the opportunity for discovery of more generalized patterns among aquatic organisms.
