Previous work has shown that many complete t haplotypes and many haplotypes in wild mice are combinations of t-specific and wild-type alleles. These exceptional alleles were confined to the distal portion of the t complex, suggesting that the nature of the chromosomal rearrangements and therefore the consequences of recombination differ between the proximal and distal portions of the complex. The first goal of the proposed studies involves testing several aspects of a hypothesis proposed to account for the origin and evolution of the to complex, by estimating the relative ages of the proximal and distal portions of the complete t haplotypes, mosaic haplotypes and their wild-type homologues through restriction fragment and sequence analysis of selected alleles, testing whether exceptional loci are confined to the distal portion of the t complex, characterizing partial t haplotypes in wild mice, identifying the boundaries of the recombination events leading to mosaic haplotypes, and estimating rates of gene flow and introgression between subspecies of Mus in Europe. The second goal involves a gene mapping test of the hypothesis that there is more than one tail interaction (tct) locus within the t complex and molecular analysis of a 35kb segment where one of the tct loci is presumably located. The t complex in house mice offers unique opportunities for studying the origin and evolution of gene complexes, especially those that act as genetic parasites by preferentially transmitting themselves to the presumed detriment of the host.
