Identification, isolation and characterization of canine minisatellite sequences

A Charomid ordered-array library containing a 2–16 Kb size fraction of MbeoI-digested canine genomic DNA has been screened with the Jeffreys multilocus probes, 33-6 and 33-15, to identify and isolate canine minisatellite sequences. Of the 48 positive clones identified, 7 were found to contain polymorphic mini-satellites with heterozygosities in the range 20–88%. The majority of the remainder were either monomorphic or dimorphic in the animals tested. Analysis of intrabreed variation in Bedlington Terriers using two polymorphic minisatellites has shown that a significant reduction occurs in the number of alleles seen compared to an agglomerated population sample, correlating with the high level of inbreeding within this breed. Flanking DNA sequence and partial repeat sequence is presented for the most polymorphic minisatellite thus far identified, cCfaMP5. The variable region in this mini-satellite is similar to human minisatellites which show a distinct purine or pyrimidine strand bias.