A missense mutation (c.1963A < G) of the complementary component 2 (C2) gene is associated with serum Ca++ concentrations in pigs

Abstract

Serum Ca++ levels play important roles in the humoral immunity. The aim of this study was to detect quantitative trait loci and the associated positional candidate genes affecting baseline serum Ca++ concentrations. A genome-wide association study was conducted in an F-2 intercross population between Landrace and Korean native pigs using the porcine single nucleotide polymorphism (SNP) 60 K beadchip and the PLINK program based on linear regression. Data used in the study included 410 F-2 pigs. All experimental animals were genotyped with 36,613 SNP markers located throughout the pig autosomes. We identified a strong association between a SNP marker on chromosome 7 and serum Ca++ levels (DIAS0002191, genomic control-corrected P = 7.7 x 10(-5)). The position of DIAS0002191 was closely located to SLA class III region containing the C2 gene encoding the complementary component 2 protein, a protein which is important in the humoral immune responses. De novo sequencing of the porcine C2 gene revealed a missense mutation [c.1963A < G (N655D)] and this missense mutation was also strongly associated with serum Ca++ concentrations (genomic control-corrected P = 5.9 x 10(-5)). Further studies are necessary to investigate the effect of this missense mutation at a functional-molecular level. In conclusion, the missense mutation of the C2 gene identified in this study may help in elucidating the genetic factors underlying humoral immune reactions.