Features of the genetic structure of the Simmental breed cattle
Abstract
Breeds of farm animals are characterized by the presence of their genetic structure, in particular, the distribution of allelic and genotypic frequencies by individual genetic and biochemical systems. The purpose of our search was to study the genetic frequencies of polymorphic loci of transferrin (TF), amylase (AM), ceruloplasmin (CR), hemoglobin (HB) and purine nucleoside phosphorylase (PN) in Simmental cattle and related breeds (Gray Ukrainian and Charolais), as well as to determine the degree of similarity between the expected loci and actual genotypes. As a result of research it was established that the genetic structure of the studied polymorphic loci of the Simmental breed was closer in animals of the Gray Ukrainian breed. In particular, at the locus of transferrin in individuals of the Gray Ukrainian breed there are alleles TF A, TF D1, TF D2 and TF E, whose genetic frequency was in the range of 0.051–0.603. The frequency of the Tf A allele in all studied breeds of cattle had a slight intergroup fluctuations (0.235–0.244), indicating their genetic similarity to this allele. At the locus of transferrin allele Tf D1 of the breed Ukrainian and Charolais were characterized by a lower frequency, however, according to the Tf D2 allele (frequency 0.603 in both breeds), they outperformed the Simmental breed by 11.7 %. The amylase locus in the studied breeds occurs with the alleles AM B and AM C, and with the allele AM A – is absent. The frequency of the AM B allele was highest in animals of the Gray Ukrainian breed, and in the AM C allele in the Charolais breed. It should be noted the high frequency of the AM B allele (0.910) in the Gray Ukrainian breed, which is due to the large number of BB homozygotes. Among the ceruloplasmin locus, the CP A allele had the highest frequency, and the CP B allele had a slightly lower frequency. In the hemoglobin locus, the frequency of HB A allele expression was the highest compared to other polymorphic systems and was in the range of 0.905–1.000. As for the HB B allele, on the contrary, the frequency of its appearance was much lower: in Simmental animals it was 0.095, in the Charolais breed it was 0.059, and in the Gray Ukrainian breed this allele was not observed. Among the alleles of purine nucleoside phosphoryls, the PN L allele was noted with a high frequency (0.697–0.846). The study of genotypes of genetic and biochemical systems of Simmental breed by loci TF, AM, SR, HB and PN shows that the locus TF, which is represented by the largest number of genotypes (10), was marked by a high degree of similarity between expected and actual genotypes with a significant difference (exception – genotype TF EE). The largest number of animals at this locus had the genotypes TF AD2, TF D1 D2 and TF D2 D2 (8 heads in each group), and the smallest – with genotypes TF AA, TF D1 D1, TF D1 E and TF D2 E (1–2 heads each). With the expected genotypes TF AF and TF EE, their real number was not detected, which indicates high heterozygosity. Amylase polymorphism is appeqred only by alleles AM B and AM C. Homozygous for allele B recorded a slightly larger number – in 23 individuals, while homozygous for allele C – only in 3 individuals, which coincides with the expected data in accordance with 21.690 and 1.690. The ceruloplasmin locus is marked by a slightly higher frequency of allele A, due to homo- (CP AA) and heterozygotes (CP AB), which appeared in 15 animals in both groups. Hemoglobin in the Simmental breed, as in most breeds of cattle, is represented mainly by allele A, and homozygotes of the BB allele are absent. Allele B is appeared in small quantities in a heterozygous state – in 4 individuals. The РN locus is appeared by two alleles (L and H), and there are no heterozygotes on the electrophoresis foregrams. There was a high frequency of the L allele of the PN locus, which is characteristic of breeds of the dairy direction of productivity. The PN H allele, which is characterized by high activity, is somewhat less common in Simmentals (only in 6 individuals). Thus, the study of genetic frequencies of the Simmental breed is necessary for the identification and early determination of the level of productivity of animals. Genetic frequencies of polymorphic loci are necessary for selection work with the breed, and can also be used in the breeding process to accelerate the rate of the breeding process. Searches of the genetic structure of the complex of genetic and biochemical systems are necessary for the research and preservation of the gene fund of local and endangered breeds of cattle.
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