Recent evolution of mousethaplotypes at polymorphic microsatellites associated with thetcomplex responder (Tcr) locus

Abstract

SummaryMicrosatellites closely associated with each member of theTcp1Ogene family were amplified simultaneously fromthaplotype and wild-type forms of mouse chromosome 17, by PCR. Thetcomplex responder (Tcr) locus, which plays a central role in transmission ratio distortion, maps within theTcp10cluster on thethaplotype. Thus the amplified set of microsatellite loci (referred to collectively asTcp10ms) provides a direct marker for this central component of the meiotic drive system associated with all naturally occurringthaplotypes. A uniqueTcp10mspattern of microsatellite alleles was obtained for a number of independent, laboratory-maintained complete and partialthaplotypes. Independenttchromosomes found in wild mice from US populations also had unique patterns, even when they were classified within the same lethal complementation group. Wild and laboratory chromosomes in thetw5group showed similarly-sized but non-identical Tcp10ms patterns, suggesting they share a recent common ancestor. These chromosomes are likely to have derived from an ancestral chromosome within the founding population of North American house mice. The Tcp10ms pattern was also shown to be useful in field studies for distinguishing among independentthaplotypes, when more than one is present within a single population.