Genomic regions associated with antibody response to sheep red blood cells in the chicken

• Published in: Animal genetics 2011-06, Vol.42 (3), p.300-308
• Main Authors: Dorshorst, B.J, Siegel, P.B, Ashwell, C.M
• Format: Article
• Language: English
• Subjects: Animals; Antibodies - genetics; Antibodies - immunology; Antibody Formation; antigens; association analysis; Body Weight; chicken; Chickens; crossing; Disease Susceptibility - immunology; erythrocytes; Erythrocytes - immunology; founder effect; Gene loci; Genetic Markers; Genetic Variation; Genome; Genome-Wide Association Study; Genotype; Haplotypes; immune response; Immune system; Immunity, Innate; Immunization; loci; major histocompatibility complex; Major Histocompatibility Complex - genetics; Major Histocompatibility Complex - immunology; Medical research; nutrients; Phenotype; Quantitative Trait Loci; quantitative trait loci estimation; sex chromosomes; sexual maturity; Sheep; sheep red blood cells; Vaccines; weight gain
• ISSN: 0268-9146; 1365-2052
• DOI: 10.1111/j.1365-2052.2010.02146.x

F ₁ and F₂ populations were generated by crossing two lines of chickens divergently selected from a common founder population for 32 generations for either high or low antibody response 5 days post-injection of a non-pathogenic antigen, sheep red blood cells (SRBCs). The number of loci with major effects on day 5 SRBC titers was estimated to be more than 7 in this population. There was a significant association between MHC haplotype and day 5 antibody titers as well as body weight at sexual maturity. A significant difference between reciprocal F₂ crosses for both 5- and 12-day antibody titers suggests that sex chromosome and/or parent of origin effects on autosomal loci have an important role in immune response. A single marker-trait association analysis on 1024 genetic markers and 128 F₂ individuals detected 11 genomic regions associated with antibody response traits and 17 regions associated with body weight gain. Several of the genomic regions identified as being associated with antibody response have been described previously, while novel regions associated with antibody response were identified on chromosomes 11 and 24. Based on the lack of overlap of the regions associated with body weight and antibody response, we conclude that while these phenotypes are inversely correlated in the selected lines, they are controlled by distinct genetic loci and may be reflective of intense selection pressure on loci affecting the partitioning of nutrients between the immune system and growth pathways.