Phylogenetic Analysis of Heat Shock Proteins in Glassy-winged Sharpshooter, Homalodisca vitripennis
The glassy-winged sharpshooter, Homatodisca vitripennis (Germar) (Hemiptera: Cicadellidae), is the major vector of Xylella fastidiosa Wells et al., the causal agent of Pierce's disease of grapes, Vitis spp. More research on leafhopper stress response is possible as more genomic information becomes available. To gain information on the stress response of the glassy-winged sharpshooter, a cDNA library was constructed from adults and fifth instars, resulting in 5,906 expressed sequence tags (ESTs). After quality scoring, 4,445 sequences underwent assembly, which produced a set of 2,123 sequences that putatively represented distinct transcripts. BLASTX analysis identified four significant homology matches to heat shock proteins (HSP), which are the focus of this study. The overall importance and function of heat shock proteins lie in their ability to maintain protein integrity and activity during stressful conditions, such as extreme heat, cold, or drought. Phylogenetic analyses using these four heat shock protein sequences provided further support of transcript by the identification of specific motifs. This study shows that highly conserved genes such as heat shock proteins are a viable supplement to ribosomal DNA in elucidating phylogenetic relationships.