IL-10 gene polymorphisms and their association with immune traits in four rabbit populations.

Interleukin-10 (IL-10) has been recently identified as a multifunctional cytokine, because of its close link with immunoregulation and anti-inflammatory responses. This study investigated the association of IL-10 genetic polymorphisms with the immune traits of New Zealand white rabbits (N-W), Fujian yellow rabbits (F-Y) and their reciprocal crosses (N-Y and Y-N, respectively). SNPs on five exons of the IL-10 gene were genotyped in 204 healthy rabbits via PCR-SSCP and DNA sequencing. Two SNPs (A1435G and G1519A, both were synonymous mutations) and six genotypes (AA, BB, CC, AB, AC and BC) were found on exon 3 and one SNP (T base insertion between loci 2532 and 2533, which caused a frameshift mutation), and three genotypes (OO, TT and TO) were present on exon 4. Allele A was the most frequent allele on exon 3 (from 0.548 to 0.771), whereas O was the most frequent on exon 4 (from 0.808 to 0.968). These four populations were all in Hardy-Weinberg equilibrium on both exon3 and exon4. Association analysis between polymorphisms and immune parameters showed that SNPs on exon 3 were significantly associated with immune traits, while SNP on exon 4 may not significantly affect immune traits, but the mechanism is yet to be further studied.