Molecular cloning and phylogenetic analysis of integrins αvβ1 and αvβ6 of one-humped camel (Camelus dromedarius)

Bactrian camels can relatively easily be infected with FMDV, but dromedary camels remain resistant even to high doses of the virus. To understand the different susceptibility between the two camel species from the standpoint of viral receptors, this work reports the sequences of the dromedary camel integrin cDNAs encoding alphavbeta1 and alphavbeta6 and compare them to those of other species, especially to Bactrian camels. The complete coding sequences for the dromedary camel alphav, beta1 and beta6 subunits were found to be 3147, 2397, and 2364 nucleotides in length, encoding 1048, 798, and 787 amino acids, respectively. The dromedary camel integrin alphav, beta1, and beta6 subunit shares common structural and functional elements with their counterparts from the other species. Phylogenetic trees showed that the dromedary camel alphav, beta1, and beta6 were clustered into the Artiodactyla group, together with those of Bactrian camel, pig, sheep, and cattle that are susceptible to FMDV infection. Compared with the Bactrian camel integrins, 4, 10, and 8 amino acid changes were found in the dromedary camel alphav, beta1, and beta6 subunits, respectively. This study will be of importance in understanding the differences of integrins as FMDV receptors among dromedary camel and other species.