Haplogroup of the modern lines of hybrid pigs
Authors: Budakva Yelyzaveta , Pochernyaev Konstantin , Lobchenko Svitlana , Borzhak Tetyana 
Published: May 2023

The aim. The study was conducted to characterize the genetic diversity of hybrid
pigs (Large White×Landrace)×Maxgro in Ukraine. Method. DNA isolation was performed from bristle samples using Chelex-100 ion exchange resin and epithelial tissue from the ear of pigs by the sorbent method. The results. The results of DNA typing of hybrid pigs (Large White×Landrace)×Maxgro from LLC "Hlobynskyi Svynocomplex" are presented. Using PCR-RFLP analysis of the polymorphism of the D-loop section, 7 mitochondrial haplotypes were determined – N, C, O, G, D, E, K. In the studied sample of pigs (n=50), the concentration of haplotypes as a percentage is determined. It was found that mitochondrial haplotypes C (24 %) were found to be characteristic of Landrace pigs, Hampshire, Wales, a wild pig (Ukraine, Poland, France); haplotype O (12%) – inherent in a wild pig and Landrace breed (Sweden); haplotype G (12 %) – peculiar to Wales breed, a wild pig (Italy, France); haplotype N (28%) is characteristic of the Large White breed of pigs, representatives are carriers of the Asian type. It is worth noting that the Asian haplotype N is characteristic of the Asian wild pig and Berkshire breed. The presented data on the hybridization of mitochondrial genomes of Asian and European origin are the basis for the creation of modern lines of hybrid pigs along the maternal line. Haplotype N refers to haplogroup A(D), and haplotypes C, O, G belong to haplogroup E. It is completely uncertain that haplotypes D (10 %), E (6 %), K (8 %) belong to haplogroup A(D). According to the results obtained, haplogroup E in hybrid pigs is dominant, however, it is haplogroup A that is the predecessor of haplogroup E. We assume opinions that pigs of the Large White breed with haplotype N, D, E, K – contain aboriginal genetic resources. Pigs with haplotype D, E, K – are the result of hybridization with European wild boars. Over time, this led to the almost complete disappearance of the primary Middle Eastern ancestors in the nuclear genomes of European domesticated pigs. The speculation that traditional seasonal cattle breeding, annual long-distance migrations that have occurred in the past, and commercial trade in nucleuses explain the observatory pattern of favorable gene flow among hybrid pigs. Conclusions. The results obtained during the study of the mitochondrial genome of hybrid pigs improved the understanding of matrilineal origin and phylogeographic model of distribution of genetic diversity of cross-border pig breeds (Large White×Landrace)×Maxgro in Ukraine. We came to the conclusion that natural selection acts very weakly on the single nucleotide polymorphism that led to the formation of the haplogroup of cross-border breeds of pigs that are found today. The obtained results of the study are evidence that European pig breeds consist of pigs with Asian and non-Asian mitochondria, some of which were formed from closely related maternal ancestors. The work was carried out with the support of the National Academy of Agrarian Sciences of Ukraine 31.01.00.07.F. "To study the pleiotropic effect of genes whose SNPs are used in markerassociated selection of pigs." SR No. 0121U109838.
Key words: hybrid pigs, (Large White×Landrace)×Maxgro, mtDNA, D-loop,
haplotype, haplogroup, PCR-PDRF.