ASSOCIATION OF GENETIC POLYMORPHISM OF LTF, MBL1 AND TLR -9 WITH RESISTANCE TO CHLAMYDIOSIS IN HOLSTEIN CATTLE

Abstract

Chlamydia is one of the most common and damaging diseases of cattle in the Republic of Kazakhstan. It is caused by intracellular parasites of the genus Chlamidia, different types of which infect individual organs or tissues of the animal. Due to the large number of potential carriers of the infection, work aimed at identifying genetic factors of resistance to chlamydia in livestock and developing test systems that allow identifying resistant and vice versa - susceptible animals in the early stages of ontogenesis. The search for genetic factors primarily focused on genes encoding the main components of innate immunity, which include genes encoding lactoferrin (LTF), the mannosebinding lectin MBL1 and the Toll-like receptor group gene TLR-9. The subjects were 186 cattle of Holstein breed, among whom 93 were cattle with a confirmed diagnosis of chlamydia. The distribution of genotypes for the polymorphic genes studied was analyzed against the theoretically expected distribution according to Hardy-Weinberg law, and a comparative analysis of the distribution of genotypes between groups of sick and healthy animals was carried out. The study identified single markers and paired genotype combinations responsible for an increased risk of morbidity/resistance to chlamydia in cattle.Одним из наиболее распространенных и наносящих значительный урон заболеваний крупного рогатого скота в Республике Казахстан является хламидиоз. Его вызывают внутриклеточные паразиты рода Chlamidia, разные виды которых поражают отдельные органы или ткани животного. Вследствии большого количество потенциальных носителей инфекции, важное значение приобретают работы, направленные на выявление генетических факторов резистентности к хламидиозу у скота и разработка тест–систем, позволяющих идентировать резистентых и наоборот – восприимчвых животных на ранних стадиях онтогенеза.