The objective of the research is to assess the rate at which particular genes ( "t complex") pass from parents to their progeny in field populations of house mice. A "+/t" male produces sperm of both the "+" form and the "t" form of the t complex. Most laboratory studies document that +/t males sire 95% +/t pups and 5% +/+ pups. This means sperm with the "t" form of the t complex fertilize more eggs than sperm with the "+" form of the t complex. Recent studies show these fertilization rates can be modified in the laboratory. With newly available techniques from molecular biology, fertilization of sperm with the "t" form of the t complex can be assessed directly in field populations. Dr. Baker will trap pregnant females in the field, then use molecular biology techniques to assess the DNA of the pregnant females and their fetuses for the "t" form of the t complex. Preliminary data indicate that most field populations of house mice have +/t mice. Understanding the dynamics of this widely distributed group of genes in house mice should provide insight for geneticists studying +/t laboratory mouse strains. Just as important, how natural selection operates on this complex of genes should be elucidated. The pilot work carried out here is expected to lead to the development of a more detailed, intensive research proposal into the dynamics of the t complex. This progression from a small preparatory phase to a well developed research project is one of the principal aims of the Research Planning Grant.
