Yekaterinburg, Russian Federation
Abstract. Genome-wide association analysis is one of the key tools for elucidating the genetic etiology of various phenotypes, including diseases and the degree of predisposition to them. Subsequently, for statistically significant genetic markers, it is necessary to conduct validation studies on independent cohorts. These post-GWAS validation studies test genetic markers that are strongly associated with the phenotype, regardless of sample size, allowing to identify false-positive results from the initial association analysis. When choosing a genotyping technique for post-GWAS validation studies, consideration should be given to the sample size and the number of genetic markers planned to be studied, since genotyping techniques differ in throughput und cost. The aim of this paper is to describe modern methods of genotyping depending on their performance and to carry out genotyping of cattle for the SNPs rs137396952 and rs134055603, for which a high degree of association with the development of ketosis was shown in previous GWAS studies. Utilized genotyping methods include TaqMan and High-Resolution Melt Analysis; genotype analysis was performed using the SNPStats web tool. When comparing the results of genotyping using these technologies, the specifity of allelic discrimination carried out using these methods was demonstrated. Testing of the genotyping results had shown that rs134055603 does not obey the Hardy-Weinberg equilibrium in the studied cohort of animals. Scientific novelty. Obtained genotyping results will be used in further association tests with physiologically valuable parameters of dairy cattle, including resistance to diseases.
GWAS, cattle, genotyping, SNP, DNA, PCR, electrophoresis
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