Genome-wide association study by gene set enrichment analysis to identify genes and pathways associated with temperament in Brahman cattle

Understanding the genetic control of temperament as a complex trait and correlated with economic traits is one of the breeding goals in beefcattle industry. The aim of the current study was genome wide association studies (GWAS) based on Gene set enrichment analysis fordetecting the loci associated with temperament traits in Brahman cattle breed. Therefore, 1370 Brahman cattle and phenotype recordsassociated with temperament traits including Exit velocity, Pen Score, and Temperament Score were used. The evaluation of genome-wideassociation was carried out using PLINK package 1.90. The gene enrichment analysis was performed by the goseq R package for identifyingbiological pathways of nearby genes in selected candidate regions and finally, GO, Metacyc, KEEG, Reactome and panther databases wereapplied for bioinformatics analysis. By Gene set enrichment analysis, the biological pathways and candidate genes of neurotransmittersecretion (NRXN3 and CACNG3), Dopamine Neurotransmitter Release Cycle (PPFIA2), regulation of neuron projection development(GRID2), neuron projection (SLC8A1 and KCNQ2), Axonal growth inhibition (RTN4R), Neurotrophin signaling pathway (MAP2K2,MAP3K5 and PSEN1) and Focal adhesion (TLN2) were identified. The detected candidate genes played an important role in differentiationof synapse, neurotransmitters, neurological diseases and disorders, oxidative and environmental stresses, hormone receptors and glucosehomeostasis. Considering the confirmation of the previous region of genome wide association and the identification of new genomic regions,the findings of this study can be useful in the genetic selection of higher production cattle through calm animals.