Preservation of field samples for enzymatic and proteomic characterization: analysis of proteins from the trophallactic fluid of hornets and yellowjackets.

Proteomics is fast becoming one of the most interdisciplinary fields, bridging many chemical and biological disciplines. Major challenges, however, can limit the reach of proteomics to studies of model organisms. Challenges include the adequate preservation of field samples and the reliance of in-depth proteomics on sequenced genomes. Seeking to better establish the evolutionary relationships of hornets and yellowjackets comprising the subfamily Vespinae, we are combining classical morphological and genomic information with a functional genomics trait using proteomics. Vespine species form highly social colonies and exhibit division of labor in almost all aspects of colony life. An extreme digestive division of labor has been reported in Vespa orientalis, in which larvae but not adult workers exhibit the capacity to digest proteins fully. This makes the colony dependent upon the amino acid-rich trophallactic fluid released to adults by larvae and implies that the V. orientalis superorganism possesses larval-specific proteases. Identifying the proteases and the species exhibiting such extreme partitioning of digestive labor will allow for tracing the phylogenetic origins and elaboration of that digestive partitioning in the Vespinae. Herein we describe methods, generally applicable to field samples, showing the preservation of proteins and proteolytic activity from adult and larval vespine trophallactic fluid.