Identification of odorant receptors from the Alpine marmot (Marmota marmota)

Alpine Marmots (Marmota marmota) are a good model to study intraspecific chemical communication among mammals. This species has been subjected to several behavioural and biochemical studies regarding both their scent-marking behaviour by cheek-rubbing, and the chemical composition of their glandular secretions. However, no molecular study has been undertaken until today on proteins from the olfactory epithelium possibly implicated in chemical perception. In this study, we identified, to our knowledge for the first time, some olfatory receptors from this wild rodent. Starting with olfactory epithelium of an Alpine Marmot, and by mean of reverse transcriptase polymerase chain reaction technique (RT-PCR), we isolated fourteen partial sequences that exhibited a high degree of homology (45-92%) with olfactory receptors from other vertebrates. Conserved identities and structural features clearly defined these Alpine Marmot sequences as members of the seven transmembrane domain olfactory receptors. All sequences were observed as belonging to known olfactory receptor families and were classified into ten subfamilies of the tetrapods OR class. Finally, Northern blot analysis revealed specific expression of these sequences in the Alpine Marmot olfactory epithelium tissue.