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