Molecular identification and differential expression of sensory neuron membrane proteins in the antennae of the black cutworm moth Agrotis ipsilon

摘要

The insect sensory neuron membrane proteins (SNMPs) SNMP1 and SNMP2 are transmembrane domain-containing proteins and are homologs of the vertebrate CD36 transmembrane proteins. It has been suggested that SNMPs play a significant role in insect chemoreception. Previous studies have demonstrated that SNMP1 is expressed in the pheromone-sensitive olfactory receptor neurons (ORNs), whereas SNMP2 is expressed in the supporting cells. In this study, we identified two full-length SNMP transcripts, AipsSNMPland AipsSNMP2, in the black cutworm moth Agrotis ipsilon (Hufnagel). The qRT-PCR results indicated that the AipsSNMPl and AipsSNMP2 transcripts were expressed significantly higher in the antennae than in other tissues of both sexes. The expression of AipsSNMPl and AipsSNMP2 in the antennae from different development stages of both sexes was investigated and was shown to begin to express in the pupae stage from 3 days before emergence and then increased dramatically at the day of the emergence, and thehigh expression levels were maintained during the following 4 days after the emergence in both sexes. The mating status had no effect on the expression levels of the AipsSNMPl and AipsSNMP2 transcripts. Consistent with previous in situ hybridization studies in other Lepidoptera insects, our immu-nolocalization results at protein level demonstrated that both AipsSNMPl and AipsSNMP2 were expressed in pheromone-sensitive sensilla trichodea but with a completely different expression profile. AipsSNMPl is more uniformed and highly expressed along the membrane of the ORN dendrites, whereas AipsSNMP2 is widely distributed at the bottom of the sensilla trichodea and highly localized in the sen-sillum lymph. Our studies provide further detailed evidence for theinvolvement and general functional role of insect SNMPs in the detection of sex pheromones and general odorant molecules.