Genome-wide association study reveals loci associated with cytokine levels in chicken serum

This is the authors' abstract. We don't add key points for this paper.

Cytokine-mediated immune responses constitute a critical line of defense that protects chickens from invasion by viruses, bacteria, parasites and other pathogens. Accordingly, the present study sought to identify genomic variants and candidate genes linked to serum cytokine concentrations in chickens, with the long-term objective of uncovering viable molecular markers to support selective breeding for improved immune traits in poultry. For this purpose, a total of 206 ten-week-old Qiandongnan Xiaoxiang chickens were selected as experimental animals. Serum concentrations of six pivotal cytokines—interferon gamma (IFN‑γ), interleukin‑1β (IL‑1β), interleukin‑6 (IL‑6), interleukin‑17 (IL‑17), interleukin‑22 (IL‑22), and tumor necrosis factor alpha (TNF‑α)—were quantified and defined as immune-related phenotypic traits. Subsequently, genome-wide resequencing data were analyzed via the FarmCPU model implemented in the rMVP package to conduct genome-wide association studies (GWAS), enabling the identification of critical loci significantly correlated with the assayed immune phenotypes. Importantly, the GWAS associated 58 loci that were significantly associated with serum cytokine traits, and these loci were located within 20 candidate genes, including SCRN1, GALT-CNTFR , and MESDC1-MESDC2 . Overall, this research delineates the population variation patterns of major serum cytokines in Qiandongnan Xiaoxiang chickens. The associated loci and candidate genes provide candidate markers for immune traits. Further functional studies are needed to confirm their roles in immune regulation.