Методологія аналізу генофонду чистопородних і помісних свиней та формування їх продуктивності на основі днк-маркерів

Abstract

Дисертація на здобуття наукового ступеня доктора сільськогосподарських наук за спеціальністю 06.02.01 – розведення та селекція тварин. – Миколаївський національний аграрний університет Міністерства освіти і науки України. – Миколаїв, 2018. Дисертаційна робота присвячена розробці методології аналізу генофонду та формування продуктивності чистопородних свиней десяти порід, що розводяться в Україні, а також помісей, отриманих на їх основі, з використанням поліморфізму мікросателітів ДНК та структурних генів: естрогенового рецептора (ESR), рецептора E. Coli F18 (ECR F18/FUT1), ріанодинового рецептора (RYR1), β-субодиниці фолікулостимулюючого гормону (FSHβ), пропердину (BF) та інсуліноподібного фактора росту (IGF2). Встановлено, що кожна із досліджуваних порід має унікальний генофонд, що зумовлює значний рівень міжпородної диференціації. Виявлено алельні варіанти локусів мікросателетів ДНК та структурних генів, що асоційовані з підвищеними показниками відтворювальних ознак свиноматок. Проаналізовано ступінь впливу генетико-автоматичних процесів, що відбуваються у різних породах свиней та визначено, що рівень генетичного різноманіття більшості порід свиней України знаходиться у загрозливому стані.

Thesis for the Doctor’s of Agriculture degree, specialty 06.02.01 – Animal Breeding and Selection. – Mykolayiv National Agrarian University of the Ministry of Education and Science of Ukraine. – Mykolayiv, 2018. The dissertation is devoted to the development of a methodology for analyzing the gene pool and the formation of productivity of pure-breed pigs of ten breeds breeding in Ukraine, and cross-breed pigs derived from them, using the polymorphism of DNA microsatellite and structural genes: the estrogen receptor (ESR), the E. coli F18 receptor (ECR F18 / FUT1), ryanodine receptor (RYR1), β- subunit of follicle-stimulating hormone (FSHβ), properdin (BF) and insulin-like growth factor (IGF2). It has been established that each of the studied breeds has a unique gene pool, which determines a significant level of interbreeding differentiation. In general, the established features are related to the specificity of the genesis of the breeds under study. It is proved that the allelic variety of various breeds of pigs is determined, first of all, by the number of rare alleles. The number of the most common alleles of loci of DNA microsatellite (occurring at a frequency of not less than 0.05) in pigs of different breeds is almost on the same level – from 2.58 in Poltava Meat breed to 4.92 in a Large White breed. A common characteristic of the studied gene pool of pigs is the excess of the expected heterozygosity index over the actual one, which indicates a shortage of animals with heterozygous genotypes. This is a consequence of the significant incidence of breeds of pigs bred in Ukraine, caused, on the one hand, by their prolonged breeding "in oneself" in conditions of closed populations (for local breeds), and on the other, by depletion of the gene pool as a result of widespread use of pedigree material of foreign origin (for transboundary breeds). For the studied array of animals, based on the analysis of the "fine" genetic structure on the basis of polymorphism of loci of DNA microsatellite, the most probable is the presence of clearly differentiated ten genetic groups, which corresponds to the actual number of the studied breeds of pigs. Different breeds of pigs are also characterized by significant intrabreed genetic differences. For pigs of Large White breed, 11 loci of DNA microsatellite (with the exception of locus SW24) showed a significant value of the index of genetic differentiation (Fst) between animals from different farms. For Duroc pigs – six loci SW24, S0155, S0355, SW240, SW911 and S0228. For pigs of Ukrainian Meat breed – at nine loci (with the exception of SW951, S0101 and S0228). For each of the herds engaged in breeding pigs of the same breed, characteristic features of allelic profiles of animals, the level of their heterozygosity, the degree of inbreeding are inherent. It was determined dependence between the indices of reproductive traits of sows and their genotype at the loci of DNA microsatellite. In sows of a Large White breed, the increased of reproductive traits are significantly associated with the presence in their genotype of the alleles SW72103, S0386178, SW24093, S0101211, SW911159, and also the alleles of the locus SW857, having a length of up to 144 bp and alleles of the locus S0228 having a length of up to 257 bp. Alleles SW24113, SW24099-109, S0101209-213 and S0101209-213 have a positive effect on the reproductive traits of sows of Ukrainian Meat breed. It was established that animals of Large White breed significantly differ from other breeds according to genetic profiles of structural genes. Only among them were individuals with genotypes of the ESRBB gene of the estrogen receptor and IGF2QQ of the gene of insulin-like growth factor; they are characterized by a high frequency of the ECRG allele of E. coli F18 receptor gene – 0.833. Associations between reproductive traits and animal genotypes by structural genes are established at the level of trends. In different herds, specific features of the manifestation of reproductive traits in animals with different genotypes for various structural genes are noted. The degree of influence of genetic-automatic processes occurring in different breeds of pigs has been analyzed and it is determined that the level of genetic diversity of the majority of pig breeds of Ukraine is in a threatening state. The highest allelic diversity (10.5 ± 0.77 alleles per locus) and the lowest rate of its loss (M-ratio = 0.425 ± 0.022 per locus) are characteristic of a Large White breed, which is caused by intensive enrichment of its gene pool due to the breeding material of a foreign origin. The functionality of the program "Accent – pedigree accounting in pigs" by the module "Genetic passport" has been expanded, which provides storage and processing of information on genetic profiles of animals by different structural genes and provides the possibility of calculating the predicted genotypes of descendants on the basis of data on the genotypes of their parents.