Screening for genes involved in antibody response to sheep red blood cells in the chicken, Gallus gallus

Antibody response, an important trait in both agriculture and biomedicine, plays a part in protecting animals from infection. Dissecting molecular basis of antibody response may improve artificial selection for natural disease resistance in livestock and poultry. A number of genetic markers associated with antibody response have been identified in the chicken and mouse by linkage-based association studies, which only define genomic regions by genetic markers but do not pinpoint genes for antibody response. In contrast, global expression profiling has been applied to define the molecular bases of a variety of biological traits through identification of differentially expressed genes (DEGs). Here, we employed Affimetrix GeneChip Chicken Genome Arrays to identify differentially expressed genes for antibody response to sheep red blood cells (SRBC) using chickens challenged with and without SRBC or chickens with high and low anti-SRBC titers. The DEGs include those with known (i.e., MHC class I and IgH genes) or unknown function in antibody response. Classification test of these genes suggested that the response of the chicken to intravenous injection of SRBC involved multiple biological processes, including response to stress or other different stimuli, sugar, carbohydrate or protein binding, and cell or soluble fraction, in addition to antibody response. This preliminary study thus provides an insight into molecular basis of antibody response to SRBC in the chicken.