No abstract

Determining the purebredity of farm animals in a breeding system is of key importance for the entire livestock industry. Purebred breeding of plant breeds is designed to ensure the production of high-value improving breeding material for commercial livestock breeding. Determination of purebredity of pigs can be carried out using single nucleotide polymorphisms (SNP). The multiplexing technology today has reached a level that makes it possible to characterize tens and hundreds of thousands of polymorphic variants simultaneously for hundreds of animals in one run of the device. For the first time, using bioinformatics methods, an analysis of genome-wide projects was carried out for 264 individuals of the species Sus scrofa located in the Sequence Read Archive (NCBI-SRA). The in silico genotype was determined for 692 SNPs, of which 59 SNPs showed a significant potential for differentiation of four commercial breeds: large white (the most significant SNPs are Chr. 6: g.85845403T> G and Chr.16: g.74053569T> C), duroc (Chr. 4: g.55661608A> G, Chr. 14: g.107689091T> C and Chr. 14: g.107939105T> C), landrace (Chr. 5: g.99925204A> G, Chr. 18: g .40100481A> G and Chr. 18: g.7664624A> G) and pietrain (Chr. 13: g.136017764T> C and Chr.17: g.47595840A> G). For breeds of duroc and pietrain pigs, the accuracy of differentiation was at least 99%, for breeds of large white and landrace pigs - over 80%, however, the sensitivity indicator characterizing the percentage of false positive results of classification was slightly over 65%. Creation of models for molecularand-genetic studies of these breeds will allow for a genetic examination of their purebredity, which will contribute to an increase in their breeding value and preservation of the national gene pool.

Genotyping of individuals of 7 commercial breeds of domestic pigs was carried out: Duroc, Landrace, Belarusian Large White, Belarusian Black-and-White, Belarusian meat, Pietrain and Yorkshire for the KDM3A and DBX2 genes. The high breed-specific potential of polymorphic loci g.58335217A>G (KDM3A gene) and g.75953650G>T (DBX2 gene) for differentiation of Duroc pigs of the species Sus scrofa domesticus was confirmed. A test model for differentiation of Duroc individuals by bioinformatic assessment of a total contribution of two SNPs of the KDM3A and DBX2 genes was proposed. This test model has no analogues in the world, and its estimation accuracy and specificity are 98.76 and 99.68 %, respectively. Using PCR-RFLP, a fast and simple approach has been developed to differentiate the Duroc breed based on the proposed test model.

Using the methods of bioinformatics, the analysis of data on sequencing of the genomes of individuals of the species Sus scrofa domesticus, which are located in the Sequence Read Archive (NCBI-SRA) database, was carried out. Genotypes were determined in silico for five breeds of domestic pigs – Duroc, Landrace, Pietrain, Large White and Yorkshire using an algorithm developed in the Python programming language. Based on a two-stage bioinformatics analysis, a wide range of SNPs with a high potential for differentiation was identified. The results obtained will be used to create express methods for determining the purity of pigs of these breeds. Extended bioinformatics analysis, which included genotyping by 7451 SNPs for 248 Sus scrofa domesticus genomes, revealed a total of 393 SNPs for all breeds for which there is a significant difference in the frequency of alternative alleles in Duroc, Landrace, Pietrain, Large White and Yorkshire pig breeds. Clusters within chromosomes are indicated, in which the density of SNPs with a high differentiating potential is the highest. For Duroc pigs, we identified 184 SNPs with differentiating potential, 24 of which showed a high differentiating potential, for Landrace pigs – 52 SNPs and 7, for Pietrain pigs – 39 and 9, for Large White pigs – 104 and 22, for Yorkshire pigs – 14 and 5, respectively.