Genome-Wide Association Study of H/L Traits in Chicken

SIMPLE SUMMARY: With the continuous increase of intensive agriculture, the poultry industry has developed rapidly. Concurrently, diseases such as avian influenza, salmonella, and Newcastle disease have brought huge losses to the poultry industry. The traditional method of disease prevention and treatment includes vaccinations, but these have been linked to concerns associated with expense and meat safety. To solve these problems, genetic breeding methods can be used. In this paper, a genome-wide association analysis was linked to heterophil/lymphocyte ratio disease-resistance traits as a means through which disease damage can be mitigated. ABSTRACT: Presently, the heterophil-to-lymphocyte (H/L) ratio is being studied extensively as a disease resistance trait. Through intricate mechanisms to identify and destroy pathogenic microorganisms, heterophils play a pivotal role in the immune defense systems of avian species. To reveal the genetic basis and molecular mechanisms affecting the H/L ratio, phenotypic and H/L data from 1650 white feather chicken broilers were used in performing a genome-wide association study. A self-developed, chicken-specific 55K chip was used for heterophils, lymphocytes, and H/L classification, according to individual genomic DNA profiles. We identified five significant single nucleotide polymorphisms (SNPs) when the genome-wide significance threshold was set to 5% (p < 2.42 × 10(−6)). A total of 15 SNPs obtained seemingly significant levels (p < 4.84 × 10(−5)). Gene annotation indicated that CARD11 (Caspase recruitment domain family member 11), BRIX1 (Biogenesis of ribosomes BRX1), and BANP (BTG3 associated nuclear protein) play a role in H/L-associated cell regulation and potentially constitute candidate gene regions for cellular functions dependent on H/L ratios. These results lay the foundation for revealing the genetic basis of disease resistance and future marker-assisted selection for disease resistance.