THE INCIDENCE OF MINI-SATELLITE AND MICRO-SATELLITE REPETITIVE DNA INTHE CANINE GENOME

We have estimated the incidence of micro- and mini-satellites in the d og genome. A genomic phage library from canine liver, with an average insert size of 16 kb, was screened to detect potentially polymorphic m icro- and mini-satellite sequences, which may be useful for the develo pment of markers of inherited diseases, for fingerprinting, or for pop ulation genetics. Synthetic oligonucleotide probes were used to search for microsatellite sequences, and minisatellites were investigated wi th eight heterologous VNTR probes. (CA)(n).(GT)(n) sequences were by f ar the most frequent, with a calculated average distance between conse cutive loci of 42 kb. The average distance between loci of tri- or tet ra-nucleotide repeats was about 330 kb. Mean inter-locus distances wer e 320 kb for (GGC)(n), 205 kb for (GTG)(n), 563 kb for (AGG)(n), 320 k b for (TCG)(n), 233 kb for (TTA)(n), 384 kb for (CCTA)(n), 368 kb for( CTGT)(n), 122 kb for (TTCC)(n), 565 kb for (TCTA)(n), and 229 kb for ( TAGG)(n). Cross-hybridization with eight human minisatellite probes wa s found at average distances of 1 400 kb; only one did not hybridize a l all. We conclude that the di-, tri and tetra-nucleotide short tandem repeats, as well as some minisatellite sequences, are potentially use ful as genetic markers, for mapping of the canine genome, and also for paternity testing and the analysis of population characteristics.