Title: Light affects gene expression during leafhopper diapause Author
Submitted to: Georgia Academy of Sciences Meeting
Publication Type: Abstract Only
Publication Acceptance Date: January 27, 2008
Publication Date: March 14, 2008
Citation: Hunter, W.B. 2008. Light affects gene expression during leafhopper diapause [abstract]. The 72nd Annual Meeting of the Florida Academy of Sciences, in conjunction with the 85th Annual Meeting of the Georgia Academy of Science, March 14-15, 2008, Jacksonville, Florida. p. 4. Technical Abstract: The condition of diapause in the glassy-winged sharpshooter, GWSS, Homalodisca vitripennis, (Hemiptera: Cicadellidae) is poorly understood. Diapause is better known from other, non hemipteran insects. We used oligonucleotide microarrays to address the specificities of transcriptional responses of adult female GWSS, which were in diapause, to three different lighting regimes. Two of these lighting regimes were known to induce oviposition in diapaused females under greenhouse conditions during winter months. Thus we examined female GWSS gene expression during diapause and during the breaking of diapause induced by light. Upon breaking diapause, the females’ ovaries become active, produced eggs and females oviposited similar to springtime conditions. The mRNA from 22 individual GWSS adult females was compared. Each individual was hybridized to a single chip, containing a gene field of 2,126 features, replicated on the slide three times. There were six individuals in the control group, and eight individuals in each treatment. Using strict criteria (greater than a twofold change in expression), we determined that a definable number of genes were differentially expressed between the diapause females within the three lighting regimes. Of the 2,126 genes surveyed, 5 genes showed an increase in expression and 2 genes decrease in expression (at least a >2.2-fold change) when comparing the control adult female GWSS to the GWSS exposed to the light treatments. Identification of the genetic basis of diapause provides genetic targets which may be subjected to silencing or down-regulation by emerging technologies in plant improvement, or through virus delivery, or endophytic bacterial expression systems. These results also are aiding the production of GWSS eggs for the mass rearing of parasitoids.