Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2009
Publication Date: 12/8/2009
Citation: Schreiber, H., Hail, D., Hunter, W.B., Bextine, B. 2009. Phylogenetic analysis of heat shock proteins in Glassy-winged sharpshooter (Homalodisca vitripennis). Southwestern Entomologist. 34:457-468. Interpretive Summary: Heat shock proteins (HSPs) were identified in the glassy-winged sharpshooter, GWSS. The overall importance and function of HSPs lie in their ability to maintain protein integrity and activity during stressful conditions such as extreme heat, cold, drought, or other stresses. The GWSS is the major vector of Xylella fastidiosa, the plant-infecting bacterium which causes Pierce’s disease of grapes. Increasing genomic information facilitates increased research on leafhopper stress responses. We conducted a genetic examination of the heat shock proteins in this insect. Genetic sequences were produced from adult and nymphs, and heat shock proteins were indentified within these sequences. This study demonstrated that the GWSS has HSP which aid in its survival and provided new sequences which can be used in further studies on GWSS genes.
Technical Abstract: Heat shock proteins were identified in the glassy-winged sharpshooter, GWSS, Homalodisca vitripennis. The overall importance and function of HSPs lie in their ability to maintain protein integrity and activity during stressful conditions, such as extreme heat, cold, drought, or other stresses. The GWSS, Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is the major vector of Xylella fastidiosa, the plant-infecting bacterium which causes Pierce’s disease of grapes. The information expands the genomic information available for leafhopper insects, and on leafhopper stress responses. Due to the importance of GWSS in the transmission and spread of Pierce’s disease, a genetic examination was made to identify the heat shock proteins in this insect. New strategies based on reducing transcriptional efficiency may one day permit the down regulation of heat shock protein functions which are key to maintaining protein stability and functions under stress, such as high and low temperatures, disease, or chemical toxicity conditions. Several cDNA libraries from adult and fifth-instars were mined from the current datasets, which resulted in a final assembled set of approximately 2,123 sequences that represented distinct transcripts. Further computer based analyses, such as BLASTX, BLASTp, Pfam, and others to identify significant homology matches to heat shock proteins, (HSP). Phylogenetic analyses were used to compares the GWSS-HSP protein sequences, two hsp20,a hsp70, and hsp90 to known sequences from other insects in the database. The analysis provided further support of HSP functions by the identification of specific motifs, or sequence patterns. This study demonstrated that GWSS HSP’s which aid in its survival had significant homology and provide new sequences needed to expand phylogenetic studies of the Hemiptera.