Expansion of olfactory receptor gene family in Australia lizard Pogona vitticeps — ASN Events

Expansion of olfactory receptor gene family in Australia lizard Pogona vitticeps (#208)

Xiuwen zhang 1 , Lijun Jin 2 , Qiye Li 2 , Hardip Patel 3 , Tariq Ezaz 1 , Stephen Sarre 1 , Arthur Georges 1
  1. Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
  2. China National Genebank, BGI-Shenzhen, Shenzhen, China
  3. The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia

Detection of environmental odor chemicals is important to help animals detect prey and discriminate palatable and noxious foods, to identify and select mates and in communication more generally. This physiological function is mediated by a group of proteins called olfactory receptors (OR). The genes encoding the olfactory receptors (OR genes) constitute the largest gene superfamily in vertebrates. By data mining, we have identified 168 OR genes from the deeply sequenced genome of Australia lizard Pogona vitticeps. These OR genes can be classified into 17 families. Three of the genes belong to ‘fish-like’ class I OR genes while the remaining 164 genes belong to mammalian-like class II OR genes which detect airborne odorants. Compared to the insectivorous Anolis carolinensis, the OR gene family of the omnivorous Pogona vitticeps is expanded, particularly, families 9, 11 and 14.  The Pogona OR genes are distributed on 40 scaffolds in the Pogona genome, with 108 of them are organized into gene clusters. OR genes showing a high level of similarity tend to be located together, suggesting that local duplication is a mechanism of OR family expansion. We compared the amino acid sequences of Pogona ORs to those in mouse with known odorant specificities. OR gene in family 52 showed homology to mouse Olfr690, a receptor gene for n-aliphatic aldehydes/alcohol – a fatty smell. This fish-like class I OR gene in Pogona may have important roles in detecting aromatic food. The expansion of OR genes is likely associated with the more diverse range of foods eaten by this species, including insects, fruits and flowers.