Mitochondrial DNA Diversity in Large White Pigs in Russia

SIMPLE SUMMARY: One of the most effective approaches to assessing populations is studying mitochondrial DNA (mtDNA) polymorphism. This work included studying variations in nucleotides in the field of a mitochondrial DNA D-loop in Large White pigs of various selections bred in the Russian Federation from 2000 to 2019 in order to define the presence of frequency distinctions of mtDNA haplotypes in Large White pigs of the Russian selection (created in the middle of the XX century) and the imported livestock of the Large White breed, which was the result of intensive selection work for increasing productive traits (growth rate, reproduction, forage costs, etc.). On the other hand, assessment of current Large White pigs from various farms of the Russian Federation is also of interest as they represent the selection of different international genetic centers. In addition, the aim of our work was to define the relationship between the allocation of mtDNA haplotypes frequencies with adaptation to different climatic conditions in Russian Large White pigs as far as breeding animals that were hardy to various environmental conditions had been one of the primary goals of that time. ABSTRACT: The Large White pig is the most commonly raised commercial pig breed in the world. The aim of this work was to investigate D-loop mtDNA in Large White pigs (n = 402) of various selections bred in the Russian Federation from 2000 to 2019. The general sample consisted of three groups: Old (n = 78) (Russian selection, 2000–2010); Imp (n = 123) (imported to Russia in 2008–2014); New (n = 201) (2015–2019). The synthesized score (Fz) was calculated by analyzing the main PCA (principal component analysis components). An affiliation to Asian or European haplogroups was determined according to the NCBI (National Center for Biotechnology Information). In the study, we defined 46 polymorphic sites and 42 haplotypes. Significant distinctions between groups Old, Imp and New in frequencies of haplotypes and haplogroups were established. The distribution of Asian and European haplotypes in the groups was Old: 50%/50%, Imp: 43%/57%, New: 75%/25%, respectively. The variety of haplotypes and haplogroups in the pigs of the group New is related to the farms in which they breed. Haplotype frequencies significantly differ between the clusters Old_Center, Old_Siberia and Old_South. This study will provide information on the genetic diversity of Large White breed pigs. The results will be useful for the conservation and sustainable use of these resources.