Unique Features of Odorant-Binding Proteins of the Parasitoid Wasp Nasonia vitripennis Revealed by Genome Annotation and Comparative Analyses

Abstract

Insects are the most diverse group of animals on the planet, comprising over 90% of all metazoan life forms, and have adapted to a wide diversity of ecosystems in nearly all environments. They have evolved highly sensitive chemical senses that are central to their interaction with their environment and to communication between individuals. Understanding the molecular bases of insect olfaction is therefore of great importance from both a basic and applied perspective. Odorant binding proteins (OBPs) are some of most abundant proteins found in insect olfactory organs, where they are the first component of the olfactory transduction cascade, carrying odorant molecules to the olfactory receptors. We carried out a search for OBPs in the genome of the parasitoid wasp Nasonia vitripennis and identified 90 sequences encoding putative OBPs. This is the largest OBP family so far reported in insects. We report unique features of the N. vitripennis OBPs, including the presence and evolutionary origin of a new subfamily of double-domain OBPs (consisting of two concatenated OBP domains), the loss of conserved cysteine residues and the expression of pseudogenes. This study also demonstrates the extremely dynamic evolution of the insect OBP family: (i) the number of different OBPs can vary greatly between species; (ii) the sequences are highly diverse, sometimes as a result of positive selection pressure with even the canonical cysteines being lost; (iii) new lineage specific domain arrangements can arise, such as the double domain OBP subfamily of wasps and mosquitoes.

Identification and expression profile of odorant‐binding proteins in Halyomorpha halys (Hemiptera: Pentatomidae)

“…These results support the hypothesis that within the Heteroptera there has been extensive duplication and differentiation of OBPs (Vieira et al ., ), especially compared with the conservative evolution of these proteins in the aphids (Gu et al ., ) and Lepidoptera (Vogt et al ., ).…”

Partial venom gland transcriptome of a Drosophila parasitoid wasp, Leptopilina heterotoma, reveals novel and shared bioactive profiles with stinging Hymenoptera

“…The functions of OBPs in insect olfaction are crucial to the environmental, reproductive, and social success of insects. The largest class of OBPs, to date, has been found in N. vitripennis (Vieira, 2012). …”

Analysis of antennal transcriptome and odorant binding protein expression profiles of the recently identified parasitoid wasp, Sclerodermus sp.

“…A total of 90 OBP genes, 225 intact OR genes, and 47 intact GR genes have been reported from the genomic data of parasitoid wasp, N. vitripennis, which is genetically similar to Sclerodermus sp. Vieira et al, 2012), comprising the largest collection of OBPs indentified in an insect thus far. We also made comparisons with two social insects because they all have more complex social behaviors than parasitoid wasps.…”