A class of highly polymorphic tetranucleotide repeats for canine genetic mapping

We have identified and characterized a new class of polymorphic markers for the canine genome from a simple tetranucleotide repeat sequence, (GAAA)n. Genetic markers derived from this repeat are highly polymorphic compared with other canine microsatellites, yet are stable enough to be useful for following Mendelian inheritance in multigeneration pedigrees. We show further that (GAAA)nrepeats are distributed throughout the canine genome and occur with sufficient frequency to be useful in the development of a framework map of the canine genome.