Determination of the genetic structure of pro-maternal pig breeds of Irish selection using mitochondrial DNA markers

Abstract

Traditionally, the mitochondrial genome is characterized as a “molecular clock” for tracking the history of phylogeny along the maternal line. Particular attention is paid to the distribution of mitochondrial DNA haplotypes among commercial pigs (Large White × Landrace) × Maxgro from RPE “Globinsky Pig Farm”, Globyno town, Poltava region, Ukraine. For the study of the genetic structure of the pigs’ hybrid markers of mitochondrial DNA — a maternal type of inheritance was used. DNA markers are a convenient tool for investigating the origin of pro-maternal pig breeds. Application of multiplex analysis PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) when examining the variable area of the D-loop between sites 15558–15917 mitochondrial genome of hybrid pigs made it possible to determine the pro-maternal haplotypes of the experimental sample (n=20). Thus, according to the multisite system developed by Pochernyaev K. F., determination of mitochondrial haplotypes of pigs, which are denoted by Latin letters from A to P allowed to determine the true pro-maternal haplotypes of the experimental sample of pigs (n=20), as evidenced by the presence of the Tas I website in the above-mentioned provisions what actually determine the haplotypes of mitochondrial DNA. According to the results of the study defined haplotypes characterize different breeds, namely 4 animals with haplotype C — Landrace (Ukraine, Poland). 6 pigs have mitochondrial haplotype N — Large White (Asian type) and 7 pigs with mitochondrial haplotype O — Landrace. 1 animal with haplotype G — wild pig and cross-border breed Wales (Italy). 2 representatives of haplotype D — not found among the breeds of domestic pigs. According to the established pro-maternal haplotypes of hybrid pigs, animals-carriers of haplotype O are representatives of Scandinavian female pigs F1 as used in uterine herds in Sweden and Ireland with the participation of the Maxgro terminal parent line in the hybridization system. Identified mitochondrial haplotypes were found to be breed-specific to hybrid pigs of Irish breeding, this is confirmed by the established polymorphism of the mitochondrial genome which is an objective marker even in complex hybridization schemes. The work was done with the support of the National Academy of Agrarian Sciences of Ukraine 31.01.00.07.F. “Investigate the pleiotropic effect gens that the SNP use in marker-associated pig breeding”. DR no. 0121U109838. Following the example of the developed systematization of the combination of restricted fragments by Pochernyaev K. F. in the future, I propose to create a database of reference haplotypes of mitochondrial DNA of pigs’ final hybrid. In the future, it will be used in further research to reconstruct the demographic history of commercial pigs of cross-border breeds.