Regulatory Mechanisms in Biosystems (Feb 2019)
Analysis of the genetic structure of a population of Lebedyn cattle by microsatellite markers
Abstract
Microsatellites – a separate class of molecular genetic markers, are widely used for the study of genetic variability, in particular in populations of animals bred by artificial selection under the influence of microevolutionary processes. The object of study is the gene pool of a population of animals of the Lebedyn cattle breed, which is under threat of extinction. The sample comprised 30 individuals from the farm "Komyshans'ke" in Sumy region. The analysis of population genetic structure was performed using 10 microsatellite loci recommended by FAO-ISAG: ETH225, BM2113, ETH3, BM1818, BM1824, ILSTS006, INRA023, TAGLA053, TAGLA12, ETH10. Amplification products were separated in polyacrylamide gels of different concentrations (5–8%), both native and denaturing. All studied loci were polymorphic. The number of detected alleles per locus ranged from 4 to 8 (on average 5 alleles per locus), the size of which ranged from 115 bp (ETH3) to 307 bp (ILSTS006). The majority of the investigated loci (except ETH3) belonged to valuable informative markers (PIC > 0.5). The most polymorphic TGLA053 (8 alleles), BM2113 (6) and ETH3 (6) loci have been identified. In general, the minimum number of alleles (4) was fixed in 50% loci. The main population genetic parameters for the studied loci have been calculated. The highest values of heterozygosity (He), and effective number of alleles (ne) was characterized for loci BM2113, ILSTS006, TGLA053 and ETH225. With the exception of ETH3 and VM1818 loci, the experimental group of animals is in a state of genetic equilibrium. The average value of the Wright fixation index indicates a tendency to increase in the number of homozygous individuals (inbreeding). Comparative analysis of genetic structure of breeds that have a common origin (Lebedyn (PJSC "Mykhaylivka"), Ukrainian grey (DPDG "Polyvanivka"), Red steppe (DPPR "Stepne"), etc.) has been carried out. The obtained results give grounds to assert that in the experimental population of the Lebedyn breed there are processes that lead to a decrease in genetic diversity. In order to overcome the negative effects of artificial reproduction in the gene pool of small populations of cattle, which include Lebedyn cattle, it is appropriate to use microsatellite markers in the selection and breeding work.
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