Submitted to: Insect Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2013
Publication Date: 1/3/2014
Publication URL: http://handle.nal.usda.gov/10113/58247
Citation: Hull, J.J., Perera, O.P., Snodgrass, G.L. 2014. Cloning and expression profiling of odorant-binding proteins in the tarnished plant bug, Lygus lineolaris. Insect Molecular Biology. 23(1):78-97.
Interpretive Summary: Insects often perceive their host plants, mates, neighbors, and predators through chemical cues (odors, tastes). The chemical cues are detected by sensory organs equipped with receptors that bind specific odor or taste molecules. Odorant binding proteins (OBP) are specialized proteins that facilitate movement of the chemical cues from the outer parts of the sense organs to the receptors. Each OBP is constructed based on information in a transcript, or genetic template. Thus, one way to detect an OBP is to identify its transcript within the insect tissues. We analyzed the transcripts of an important pest insect, the tarnished plant bug, and found 33 transcripts with sequence similarity to OBPs. Several of the transcripts occurred predominantly in the antenna, suggesting the corresponding OBPs play a role in olfaction (smell). Other transcripts were more common in the insect mouthparts and legs, which suggests a role in gustation (taste). These findings provide base-line information to guide future work on chemical communication in this pest insect. Better understanding of how this insect uses and responds to chemical cues may lead to pest control technologies that interfere with essential chemical communications.
Technical Abstract: In insects, the perception and discrimination of odorants requires the involvement of odorant binding proteins (OBPs). To gain a better molecular understanding of olfaction in the agronomic pest, Lygus lineolaris (tarnished plant bug), we used a transcriptomics-based approach to identify potential OBPs. In total, 33 putative OBP transcripts, including the previously reported Lygus antennal protein (LAP), were identified based on the characteristic OBP Cys signature and/or sequence similarity with annotated orthologous sequences. The L. lineolaris OBP (LylinOBP) repertoire consists of 20 "classic" OBPs, defined by the spacing of six conserved Cys residues, and 12 "Plus-C" OBPs, defined by the spacing of eight conserved Cys and one conserved Pro residue. Alternative splicing of OBP genes appears to contribute significantly to the multiplicity of LylinOBP sequences. Microarray-based analysis of chemosensory tissues (antennae, legs, and proboscis) revealed enrichment of 21 LylinOBP transcripts in antennae, 12 in legs, and 15 in proboscis, suggesting potential roles in olfaction and gustation respectively. PCR-based determination of transcript copy number for a subset of the LylinOBP genes across multiple adult tissues yielded results consistent with the hybridization data.