title: Genetic evidence for the existence of interleukin-23 and for variation in the interleukin-12 and interleukin-12 receptor genes in the horse.
abstract: Immune loci, characterized by features reflecting their role in defense reactions and consequently related to evolutionary mechanisms, including polymorphisms or association with disease are suitable candidates for comparative analysis. Interleukin-12 and related cytokines are key molecules regulating natural and specific immune responses. In this study, we analyzed four horse IL12-related genes: IL23p19, IL12Rbeta2, IL12p40, and IL12p35. Genomic nucleotide sequence of the horse IL23 p19 sub-unit encoding gene was determined. The horse IL23p19 gene consists of four exons; its total mRNA length is 1004 bp, with a coding region of 579 bp. The predicted amino acid sequence of the horse IL23p19 sub-unit showed 88.0% sequence identity with the human sequence. A partial genomic sequence highly homologous to human IL12Rbeta2 suggesting existence of this gene in the horse was retrieved. Single nucleotide polymorphisms (SNPs) were identified in all four genes analyzed. PCR-RFLP genotyping was developed for selected SNPs. Inter-breed differences in allele and genotype frequencies were observed in IL12p35 SNP 242. The results showed that horse IL12-related genes are comparable to their counterparts in other mammalian species in terms of their structure and their genetic variation.
authors.affiliation: Institute of Animal Genetics, Faculty of Veterinary Medicine, Palackého 1/3, CZ-612 42 Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kralik
authors.forename: Jan
authors.initials: J
authors.lastname: Matiasovic
authors.forename: Petr
authors.initials: P
authors.lastname: Horin