Aim. The aim of our research was to analyze the population-genetic processes in different dairy breeds using highly polymorphic molecular and genetic markers (DNA microsatellites). Methods. We used 10 loci recommended by the International Society for Animal Genetics (ISAG) to analyze 88 DNA samples of the two most abundant dairy breeds of cattle in Ukraine – Ukrainian red-motley dairy and Ukrainian black-and-white dairy breeds. Using formulae that related the expected linkage disequilibrium (LD) to the effective population size (Ne), Ne was estimated. Results. The work presents the results of the study on genetic processes in the populations of Ukrainian red-and-motley breed using 10 microsatellite loci of DNA. It was shown that, being highly polymorphic multilocus genetic systems, microsatellites of DNA are highly informative markers of populationgenetic processes, occurring in the populations of cattle. Conclusions. The studied populations of Ukrainian dairy cattle breeds are impacted by population-genetic and genetic-automatic processes. In particular, the effect of the latter on Ukrainian red-and-motley dairy breed was noted. These animals had notable signifi cant loss of rare alleles and the manifestation effect of “bottle neck”. The values obtained testify to a low level of inbredness in these populations. The effective population size in the studied Ukrainian dairy cattle breeds was estimated in the approximate range of 397–555 heads which testifi ed to a favorable condition of the population of Ukrainian red-and-motley dairy cattle and a critical condition of the Ukrainian black-and-white dairy breed.

Aim. Our work was aimed at the evaluation of genetic diversity of three domestic equine breeds which differ by the history of their formation and use. Methods. Genotyping of DNA samples of three breeds of horses, namely, Hucul (78 animals), Thoroughbred (51 animals) and Ukrainian Saddle Horse (152 animals), was conducted by 11 microsatellite loci, recommended by the International Stud Book Committee (ISBC) and the International Society for Animal Genetics (ISAG). The mathematical analysis involved parametric and non-parametric methods of statistics. Results. The results of polymorphism analysis of the gene funds for Hucul, Thoroughbred and Ukrainian Saddle horses by 11 microsatellite DNA loci were fi rst presented in Ukraine. It was demonstrated that the study of microsatellite DNA loci allows both determining the reliability of origin of pedigree animals and controlling population processes in different breeds and the polymorphy of the very breeds. Conclusions. The molecular and genetic analysis of equine breeds, differing by their provenance, demonstrated specifi cities of genetic structure of each breed, which correspond to the formation history of their gene funds. The populational-genetic analysis using different mathematical methods is recommended for the purposes of evaluating and forecasting microevolution processes, controlling gene fund formation both during the breeding work and within the system of preserving genetic biodiversity

Aim. The aim of our work was to investigate the interbreed differentiation of Ukrainian Red-and-Motley and Black-and-White dairy cows based on the results of the analysis of allelic and genotypic polymorphism of DNA microsatellites. Methods. Genotyping of 88 DNA samples of two most numerous dairy cattle breeds in Ukraine – Ukrainian Red-and-Motley and Black-and-White dairy cows – was conducted by 10 loci, recommended by the International Society for Animal Genetics (ISAG). The analysis of allelic and genotypic polymorphism was performed using parametric and non-parametric methods. Results. Informative value of DNA microsatellites as markers of genetic processes, which take place in the populations of domestic animals, was assessed. Conclusions. The investigated breeds demonstrate a reliable level of genetic differentiation with a high level of similarity.

Aim. Our work was aimed at investigating the specificities in the formation of the genetic structure of populations depending on the productivity direction of cattle, bred in Ukraine, using single locus DNA fragments, and studying the impact of the parental form on genetic polymorphism of modern intensive specialized breeds as a factor. Methods. The following methods were used in the work: veterinary methods (peripheral blood sampling); molecular-genetic meth- ods (the isolation and genotyping of DNA samples of dairy (83 animals), meat (192 animals) and aboriginal (43 ani- mals) cattle, bred in Ukraine, were performed by 10 microsatellite loci from the list, recommended by the International Society for Animal Genetics (ISAG); the complex of statistics methods was used for mathematic-statistical analysis, using modern software. Results. The analysis by 10 microsatellite loci demonstrated the specificities of genetic dif- ferentiation and the similarities between the investigated cattle populations, bred in Ukraine. Our results provide new information about the impact of artificial selection factors on single locus DNA fragments under the specialization of cattle breeds. The impact of the factor of ancestral form on the genetic structure was determined and confirmed by the same polymorphism spectra of the investigated DNA fragments in the maternal and derivative breeds. Another con- firmation was found in the differences, observed in animals of different productivity directions, which are a probable result of the breed-forming process, demonstrated by the results of the mathematic calculations of the data obtained. It was shown that microsatellite DNA loci are highly informative markers of genetic processes, occurring in domestic cattle populations. Conclusions. The specificities in the formation of the genetic structure of populations depending on the productivity direction of animals were determined. The impact of the parental form on genetic polymorphism of modern intensive specialized breeds was noted. It was found that among 10 microsatellite loci, used by us, there were loci in each group of animals, regarding which the hypothesis about their neutrality was reliably rejected accord- ing to the results of Ewens-Watterson test: for dairy cattle (INRA023, ETH3, ETH225, BM1824, BM2113, ETH10 and SPS115), for meat cattle (TGLA122 and ETH225), and for aboriginal cattle (TGLA126, INRA023 and TGLA227). We determined a high level of genetic diversity, remarkable for each investigated cattle population, bred in Ukraine, and general tendencies of differentiation in the selected populations depending on the targeted breeding work, on the level of polymorphism of microsatellite DNA loci (Friedman’s test: P < 0.01), and a similar genetic picture for a number of loci of investigated DNA fragments, which may be related to the history of creating these breeds.

The analysis of allelic polymorphism of five industrial egg crosses of chickens by five microsatellite DNA loci (ADL0268, MCW216, LEI0094, ADL0278, and MCW248) was carried out. DNA loci were chosen according to the recommendations of the International Society for Animal Genetics (ISAG). Based on the results of mathematical-statistical processing and data analysis, the spectra and frequencies of allelic variability, the peculiarities of allele pools, were identified, and unique alleles were identified. In general, the species Gallus gallus is characterized by a specific character of allelic spectra for all investigated microsatellite DNA loci (P <0.001). The highest rates of allelic variability were recorded in brown crosses "Lohmann brown" and "Hisex brown" (Na (LimNa)=(9.2 (5-17) and 7.4 (6-11), respectively). The studied crosses were characterized by a shift in allelic spectra towards a decrease in the fragment length. “Lohmann white” stands out among the birds of other crosses by high consolidation for individual alleles for all studied microsatellites (from ADL278114 – 0.343 and ADL268108 – 0.485 to LEI094259 – 0.720, MCW0248213 – 0.785 and MCW0216137 – 0.920). Unique alleles with the highest frequency were found in brown cross chickens, and in the “Hy-Line W-98” bird, they were not found. The number of unique alleles identified varied from 1 ("Hisex white") to 11 ("Lohmann brown"). Locus LEI094 turned out to be the most polymorphic in terms of the number of unique alleles – 10 such allelic variants were identified for it. No unique alleles were identified at the ADL0268 locus. The obtained estimates criterion χ2 of K. Pearson indicate significant differences in the frequency distribution of alleles for all studied loci. When using the MICROSATELLITE ANALYSER software, it was found that the nature of the variability of the studied microsatellite DNA loci in five industrial crosses of the egg chickens, both in the number of identified alleles and in the nature of their distribution, corresponded to the stepwise mutation model (SMM).