Genome-Wide Identification of Regions Associated with Heat-Tolerance and Newcastle Disease Virus Resistance in Chickens

Ever increasing global temperature fluctuations have led to a huge economic loss for agricultural producers worldwide. In addition to these temperature fluctuations, stressors such as disease can greatly impact food production especially for rural farmers in the developing countries that depend on poultry as a critical food source. In this study, we attempted to identify genomic regions associated with heat-tolerance and Newcastle disease resistance in chickens. 550 Hy-Line Brown layer chicks were exposed to 35°C at 60% humidity starting at 14 days old. Physiological responses to heat stress were measured using the iSTAT device at 14, 23, and 27 days of age. The chicks were then inoculated with the Newcastle Disease Virus (NDV) at day 21 of age. Virus titers from tears at 2 and 6 DPI were measured using qRT-PCR. The birds were then genotyped using an Affymetrix 600K SNP chip and genome wide association studies (GWAS) with these phenotypes were performed using PLINK. Preliminary analysis has revealed a potentially interesting 10kb region of Chr12 significantly associated with sodium and glucose levels that have previously been described as potential physiological indicators of heat stress. Furthermore, virus titer and antibody response association analysis has also shown strong evidence with a cluster of significant SNPs within 100kb region in Chr2.

Support: USAID Feed the Future Innovation Lab for Genomics to Improve Poultry, and Hy-Line International.