FREQUENT DNA POLYMORPHISMS EXIST IN INBRED CBA J AND C3H/HEN MICE/

Although occasional DNA polymorphisms have been observed in inbred mic e, CBA/J and C3H/HeN mice have two microsatellite alleles at over 1/3 of microsatellite loci tested. Since DNA polymorphisms were not detect ed in DBA/2J, C57BL/6J, and BALB/cJ, the frequency of microsatellite p olymorphisms appears to be strain specific, Thus, genetic studies in i nbred mice require testing for preexisting polymorphisms, The polymorp hisms detected in CBA/J mice appear to be stable and do not represent microsatellite instability or a mutator phenotype. Somatic mosaicism w as not observed and no more than two alleles were detected per locus. CBA/J propagated only by brother-sister mating maintained seven of eig ht polymorphisms over 5 years, These data suggest that the polymorphis ms are due to an inherited trait and that the pattern of inheritance i s not due to Mendelian distribution. As breeding analysis was not perf ormed, the pattern of allelic inheritance is unknown. (C) 1996 Academi c Press, Inc.