Genetic analysis of a closed herd of Japanese Black cattle in Tajima district using DNA polymorphisms

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To utilize a closed herd of 'Tajima cattle' having high quality beef for genetic improvement of Japanese Black cattle effectively, genetic constitution of the herd was investigated by using DNA polymorphism analysis. The analysis was also applied to parentage identification.1. DNA fingerprinting was examined with a M13 phage DNA probe in the cattle of 42 families extracted from the herd. The parentage of each family was identified by using some restriction endonucleases such as Hae III.2. A linear regression of Genetic Similarity level(X) estimated from DNA fingerprints on relationship coefficient(Y) yielded the equation, Y = 1.149X - 0.026, with highly significant correlation coefficient,indicating that DNA fingerprinting could be applied to estimate the relation coefficient in cattle.3. Cluster analysis based on banding patterns in DNA fingerprints showed that the herd is roughly divided into two groups. This result depended mainly on the frequencies of two bands(minisatellite loci).4. Using bovine cDNA of lipoprotein lypase as a probe, restriction fragment length polymorphisms(RFLP) have been examined in the herd. The 1.3kb probe(5'-half containing open reading frame) gave distinctive RFLPs with 5 restriction enzymes such as Pst I. Types of RFLP being given with each restriction enzyme were closely related to each other and expressed as haplotypes A and B, which suggests all RFLP types are linking. It was shown that Aand B RFLP types are codominantly inherited. Heifers of 116 Japanese Black of the herd were classified into 3 groups, AA(15 heads), AB(65) and BB(35), with the gene frequencies of 0.418 (haplotype A) and 0.582 (B).