Résumé
Receptors play a crucial role in determining the host specificity and tissue tropism of virus. Foot-and-mouth disease virus(FMDV)has been showed to use four integrins, ?v?1, ?v?3, ?v?6 and ?v?8 as receptors to initiate infection and ?v?6 functions as the major receptor.The cDNA encoding bactrian camel integrin ?6 from the lung tissue was cloned and sequenced. The 2367bp cDNA of bactrian camel integrin ?6 encodes a polypeptide of 788 amino acids consisting of a 26-residue putative signal peptide, a 681-residue ectodomain with 8 potential N-linked glycosylation sites and 58 cysteine residues, a 29-residue transmembrane domain, and a 52-residue cytoplasmic domain with a NPLY motif and 1 potential N-linked glycosylation site. The nucleotide sequence similarity of integrin ?6 between bactrian camel and cattle, pig, sheep, human, mouse, Norway rat is 91.1%、91.8%、90.6%、90.5%、83.7%、84.1%, and the amino acid sequence similarity is 94.3%、93.4%、93.4%、93.7%、88.7%、88.6%, respectively. The bactrian camel ?6 gene exhibited the higher sequence homology with the ?6 gene of cattle, pig and sheep, indicating their close genetic relationships. It is possible that host tropism of FMDV may related to divergence in ?6 receptors among different species.