Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 1998
Publication Date: N/A
Technical Abstract: The tarnished plant bug (TPB), Lygus lineolaris, is a serious pest of cotton. Our previous electrophysiological and morphological studies showed sensilla which house receptor cells for plant or insect odors appear during the final molt from fifth instar nymph to adult in the TPB. We have utilized fifth instar nymphs vs adults as a developmental system to identify antennal gene products which may be correlated with transition to adult olfactory function. Here we summarize results from an interdis- ciplinary approach, which characterizes a Lygus antennal-specific protein (LAP) of 15 to 16 kDa most likely involved in chemical reception in TPB. LAP antiserum was developed and used in Western blotting to show that LAP was found in antennae of Lygus spp. but was not detectable in distant relatives such as Podisus or Nezara spp. Immunocytochemical analyses localized LAP to the sensilla of the antenna. Immunogold labeling of thin sections revealed that LAP was associated with the extacellular, sensillar lymph. LAP was associated with specific subtypes of sensilla, specifically the multiporous olfactory sensilla. Using primers designed from LAP N-terminal amino acid sequence, we isolated and cloned the cDNA encoding LAP via reverse transcription and polymerase chain reaction. The full length cDNA sequence indicated that LAP is related to Odorant Binding Proteins previously found in the fruit fly, Drosophila melanogaster. In situ hybridization of the LAP cDNA localized the mRNA for LAP to specific cells beneath the antennal cuticle near the sensilla. As a whole, these physiological, structural, and anatomical studies indicate that LAP is an Odorant Binding Protein of TPB; as such, LAP is the first biochemical step in the pathway that recognizes behaviorally important olfactory signals.