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Reticulitermes flavipes (Isoptera: Rhinotermitidae) proteomics

Bowen, Charles Jerry, Jr.
Scope and Method of Study: The objectives of this study were to establish a system for analyzing the termite proteome, develop a standard protein reference map for Reticulitermes flavipes, begin putative characterization of the proteome, and compare differences among colonies and between the worker and soldier castes. The system was established using two-dimensional gel electrophoresis for protein separation and coomassie brilliant blue stain for protein visualization. Proteins were analyzed with MALDI-TOF mass spectrometry and tandem mass spectrometry (MS/MS). Resulting data were searched against protein databases for putative identification. A standard protein reference map was generated and used to compare differences among colonies. A reference map for the soldier caste was generated to allow comparison between worker and soldier castes.
Findings and Conclusions: Two-dimensional Reticulitermes flavipes protein maps were comparable demonstrating less than 10% of differentially expressed proteins among castes. However, comparison of two-dimensional protein maps of worker vs soldier castes demonstrated substantial quantities (~50%) of differentially expressed proteins. Mass spectrometry was undertaken on 310 worker proteins and an additional 142 differentially expressed soldier proteins. Overall, database searches yielded high-confidence putative identifications for 18.7% of the proteins. Comparison between MALDI-TOF and MS/MS yields revealed a fivefold increase in identifications from 7% to 34%, respectively. Hexamerins were the protein group most commonly identified from a termite protein source.