Phylogenetic changes in resistance indicators of domestic and wild pigs

Abstract

Aim. The decisive factor in the transformation of the pig was domestication, that is, changes as a result of domestication and breeding in an artificial environment. The phylogenesis of pigs was carried out – wild boar (Sus scrofa ferus) – domestication – primitive domestic pig – aboriginal, well adapted to local conditions. This is a fairly productive pig – a large-sized greasy-type breed – a specialized modern light-type breed (Sus scrofa domestica). Modern research shows that in the process of domestication and evolution of animals, in particular the wild boar and the pig, the role of mutations is quite small, because it is very rare in the genome of the species (only 10 ^{- 6})[6]. Breed differences arise because new environmental conditions cause changes not only in the genome, but also changes in the chromosomal set of nuclei, and in them regulatory, rather than structural genes. Therefore, despite the different number of chromosomes in the wild boar (36) and in the domestic pig (38), they easily interbreed and give fertile hybrid offspring, phenotypically more like a pig, with a clear dominance of boar heredity. However, in hybrids, these transformations lead to a sharp decrease in adaptive capacity in comparison with the wild boar. The aim of our research was a comparative study of the European wild boar and large white pigs. The task is to establish phylogenetic changes in some organs and defense systems in pigs during domestication. Methods. In the research were used zootechnical, morphological, genetic and biochemical research methods. Results. A comparative research of domestic and wild pigs showed that wild species have a more active protective function of the body, primarily due to the cellular mechanism (lymphoid system, plasma reaction in combination with humoral factors). Based on our research, wild boar can be a donor of valuable adaptive properties for increasing the resistance and vitality of modern pig breeds. Conclusions. The study of the phylogeny of the immune system shows that the spleen and thymus are already present in lower vertebrates. In the ontogeny of the immune system in a pig, as in phylogeny, the spleen and thymus are first laid, and then the development of secondary lymphoid organs begins, which is associated with the development of the cellular defense mechanism of animals.
Keywords: phylogenesis, domestication, breed, genome, species, resistance.