DNA-FINGERPRINTING ANALYSIS OF BOOROOLA PEDIGREES - A SEARCH FOR LINKAGE TO THE BOOROOLA GENE

Seven minisatellite probes from a variety of sources were used to anal yse 11 paternal half-sib families in which the Booroola gene was segre gating. A total of 402 bands that showed segregation in the pedigrees were examined for linkage to the Booroola gene. None of the bands show ed segregation with the Booroola gene. The most likely evidence for a linked band was produced by the HaRas HVR probe in Family 902 (theta = 0.0; LOD 2.3). The conclusion, however, is that the minisatellite pro bes used in this study could not be used as markers for the Booroola g ene. The study highlighted problems associated with the use of minisat ellite probes in linkage studies in half-sib families. The complex ban ding patterns found on fingerprinting gels was a major source of scori ng error. In a few cases both of the sire's alleles could be identifie d at a particular locus, but in most cases only one of the alleles cou ld be identified. For the most part, the bands had to be treated as do minant alleles. The contribution of dam alleles to the banding pattern could only be estimated. There was an indication that minisatellite l oci in sheep are clustered in particular regions of the sheep genome a s the rate at which bands segregated with each other was higher than o ne would expect from loci randomly distributed throughout the genome.