[Polymorphism of untranscribed spacer rDNA as a molecular genetic marker in population studies of cattle].

Variable polymorphic patterns were detected using EcoRI-SalI fragment of bovine rDNA, including 3'-end of 28S rRNA gene with the adjacent portion of the transcribed spacer, as a probe for hybridization. Some features of these polymorphic patterns are similar to DNA fingerprints detected with the M13 probe. Bovine rDNA spacer polymorphism was used as a molecular genetic marker for population analysis of individual specific patterns of 4 cattle breeds with the help of the Jeffreys' method. It was supposed that the probability of identical fingerprints appearance could be the characteristics of heterogeneity of cattle populations. The observed length of polymorphic gragments ranged from 2000 to 6000 bp. The mean number of fragments per individual for all breeds was 15.05. The probability of identical patterns appearance was very high: from 1.18 x 10(-5) in ajshir's breed to 1.43 x 10(-7) in "white and black"s' breed. So, high probability seems to be dependent on the high allelic frequency and the way of breeding.