SELECTION AND ASSESSMENT OF ISSR-MARKERS FOR ANALYSIS OF SEPARATE CATTLE POPULATIONS
Authors: Мaherovska О. M. 
Published: July 2021

The article covers molecular genetic analysis of intermicrosatellite DNA sequences of dairy cattle productivity. Molecular markers based on DNA polymorphism were used for this monitoring. Such markers make it possible to assess quickly the genetic polymorphism of taprin in the herd. Іnsofar as a large number of intermicrosatellite repeats is in the genome of cattle, that increases the probability of detecting polymorphic loci. The ISSR markers selected for the study are based on multiclocus synthesis in polymerase chain reaction (PCR) and allow an objective study of the breed and interbreed diversity. And it makes possible to assess quickly and accurately genetic diversity for the presence of genes associated with economically useful traits. The purpose of this work is the selection and evaluation of ISSR-markers for the analysis and study of genetic diversity of Ukrainian and imported breeds of dairy cattle. Samples of biological material from representatives of three herds of cattle (Ukrainian Red-and-White spotted dairy, Montbeliard breed and their crossbreeds) were selected for the study by the method of groups-analogues. For the analysis of this material the generally accepted zootechnical methods of studying of a selection material and methods of an estimation of animals on molecular – genetic markers are included. According to standard methods, DNA was isolated from peripheral blood lymphocytes using a set of reagents "DNA Sorb B". Amplification of total DNA with ISSR primers was performed on a thermal cycler "Tertsyk" ("DNA technology" of the Russian Federation). Electrophoretic separation of DNA fragments was performed in an agarose gel according to conventional methods. The size of the obtained PCR products was detected using a molecular weight marker SM1343. As a result of the study of the biological material of these animals, the obtained ISSR-PCR products were quite heterogeneous. The vast majority of polylocus spectra had clear discrete bands, but there were amplicons without clear discrete bands. Analyzing the results of the study of the genetic structure of animals of the Ukrainian Red-and-White dairy breed, using primers ISSR-1, ISSR-2, ISSR-3 and ISSR-4, the range of obtained PCR products ranges from 250 bp. up to 3000 bp. The range of amplification products in Montbeliard animals has a smaller range and ranges from 250 bp, respectively. up to 1500 bp.The obtained amplicons for the use of primers ISSR-1 and ISSR-2, ISSR-3 and ISSR-4 in the turf of Ukrainian Red-and-White dairy and Montbeliard breeds have sizes from 350 bp to 2000 bp. Having analyzed the information you can determine the distribution of the number and length of DNA fragments using 4 ISSR-markers. The total number of amplified DNA fragments varies depending on the primer from 21 to 106, and their size ranges from 250 BP up to 3000 bp. Based on the analysis of DNA plymorphism, it is possible to assess the heterogeneity of selected populations of cattle. Thus, as a result of studying the genetic structure of animals of two breeds of dairy cattle and their crossbreeds by intermicrosatellite DNA loci, their individual polymorphism was revealed. The amplification products have significant variations depending on the primer used. Primers ISSR-1 and ISSR-2 were the most informative for the analysis of cattle DNA polymorphism.