Abstract
Understanding the biological mechanisms underlying tick resistance in cattle holds the potential to facilitate genetic improvement through selective breeding. Genome wide association studies (GWAS) are popular in research on unraveling genetic determinants underlying complex traits such as tick resistance. To date, various studies have been published on single nucleotide polymorphisms (SNPs) associated with tick resistance in cattle. The discovery of SNPs related to tick resistance has led to the mapping of associated candidate genes. Despite the success of these studies, information on genetic determinants associated with tick resistance in cattle is still limited. This warrants the need for more studies to be conducted. In Africa, the cost of genotyping is still relatively expensive; thus, conducting GWAS is a challenge, as the minimum number of animals recommended cannot be genotyped. These population size and genotype cost challenges may be overcome through the establishment of collaborations. Thus, the current review discusses GWAS as a tool to uncover SNPs associated with tick resistance, by focusing on the study design, association analysis, factors influencing the success of GWAS, and the progress on cattle tick resistance studies.
Highlights
A potential alternative approach to control ticks would be the use of genomic information, which entails the exploitation of genetic variation in host resistance to tick infestation
Its underlying principle is to seek correlation between phenotype and genotype based on a non-random association of alleles at two or more loci [17,18]. This Genome wide association studies (GWAS) approach has successfully uncovered genetic determinants associated with disease susceptibility and resistance in humans, animals, and plants [19,20,21] using this approach to uncover genetic determinants associated with traits which follow polygenic patterns of inheritance, such as tick resistance, is not straight forward, since such traits are controlled by multiple genes
This is because GWAS is able to detect variants that can be in linkage disequilibrium (LD) with the causal variant, and this information could be used to narrow genomic regions that harbour causal variants [24,25], providing genetic determinant information that could be useful for the genetic selection of economic traits, such as tick resistance in cattle
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. A potential alternative approach to control ticks would be the use of genomic information, which entails the exploitation of genetic variation in host resistance to tick infestation. The success of this approach depends on the discovery of genetic determinants associated with low tick load in cattle. Genome-wide association studies (GWAS) are increasingly becoming the common experimental approach to investigate SNP markers associated with various economic traits in animal production. This approach operates by associating the phenotype with the genotype data to investigate the causal genetic variants for traits of interest using statistical models. This paper reviews GWAS as a genetic tool to identify genetic variants associated with resistance to ticks in cattle
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
