Submitted to: Chemical Senses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/1999
Publication Date: N/A
Interpretive Summary: Chemical signals emitted by host plants or animals mediate numerous behaviors of insects. Although many of these chemical signals have been identified, components of the chemical sensing system of the insect by which they are detected are poorly understood. We have sequenced and expressed a component of the chemical sensing system called an odorant binding protein (OBP) in the tarnished plant bug, Lygus lineolaris, a pest of more than 100 agricultural crops from potatoes to cotton. Our results greatly expand the distribution of OBPs in insect, and their diversity correlates with the structural diversify of chemical signals used by them. Since OBPs are currently thought to be the initial biochemical step in odor discrimination, knowledge of their structure could lead to the discovery by insect molecular biologists, biochemists and physiologists of chemicals to disrupt behavior of pestiferous insects.
Technical Abstract: Insect Odorant Binding Proteins (OBPs) have been identified from several Orders of homometabolous insects belonging to a presumed monophyletic division known as the Endopterygota. Recently, LAP, an antennal protein with OBP-like properties, was identified from Lygus lineolaris, a hemipteran insect representing the Hemipteroid Assemblage, a sister division to the Endopterygota. In situ hybridization reveals LAP mRNA expression in cell clusters associating with olfactory sensilla; expression is adult specific, although it initiates in developing adult tissue during the transitional period that precedes the adult molt. The full length sequence of LAP was related to the OBP-protein family, especially OS-E and OS-F proteins of Drosophila, ABPX proteins of Lepidoptera and OBPRP proteins of Coleoptera. Current models of OBP action suggest that OBPs are the first biochemical step in odor reception capable of some level of odor discrimination. Assuming that identification of LAP expands the phylogenetic depth of that family and its underlying role in odor detection to encompass all members of the Endopterygota and Hemipteroid Assemblage, which include many species of considerable agricultural and health-related importance.