Abstract: Objective To find out the relationship between single nucleotide polymorphism (SNP) genotypes of canine olfactory receptor (OR) genes and odor detection performance in working-dogs. Method The multiplex Sequenom MassARRAY SNP system was adopted to detect the several SNP sites of OR genes and to analyze the correlation between different SNP genotypes and olfactory ability of working-dogs. Results The representative 68 SNP sites from canine OR genome were selected. The detection rate of this system in 3 breeds of Spinger Spaniel, Labrador Retriever and German Shepherd dog were all above 90%. The results showed that 23 SNP sites were found to be significantly correlated with the sniffing ability of working dogs (P< 0.05). But after the Bonferroni correction and FDR_BH correction, only 4 SNP sites including COR52AC1_436, rs850523383, CfOR0149_364 and CfOR0055_265 were found to be significantly correlated with sniffing ability (P< 0.05, BONF) and extremely significant (P< 0.01, FDR_BH). Conclusion Four major SNP sites of OR gene were screened, which significantly affected the sniffing ability of working dogs. A molecular genetic detection method was preliminary established to identify working-dogs potential sniffing ability, which was appropriate for Spinger Spaniel, Labrador Retriever and German Shepherd dog.

Key words: Sequenom MassARRAY, Olfactory receptor (OR) gene, Single nucleotide polymorphism (SNP), Working-dog, Sniffing ability