Bat salivary proteins segregate according to diet

Whole saliva samples were gathered from four insectivorous (Myotis tricolor , Pipistrellus africanus, Mops condylurus, and Chaerephon pumilla) and two frugivorous (Epomophorus labiatus, E. minor) bat species following a 6-10 h our fasting period and immediately stored in liquid nitrogen. Proteins with in the samples were visualized by SDS-PAGE techniques modified for saliva. With the exception of E. minor, each species is represented by four to five individuals. Only minor fluctuations in protein banding patterns were enco untered among conspecifics. However, frugivores exhibit a major band at 60 Kd that is absent in insectivores, and insectivores exhibit a major 40 Kd b and that is lacking in frugivores. Peptides from three sets of bands were e xtracted directly from the gels after in-sine proteolysis and isolation usi ng HPLC. Comparison of amino acid sequences to the PIR, EC, and SwisProt da tabanks did not yield any compelling similarities, though some interesting potential matches were generated. Based on their molecular weights, potenti al identities of the proteins are discussed with respect to their roles in digestion and the maintenance of the oral cavity. These data constitute the first comparative analysis of bat salivary proteins and suggest that this novel source of data will prove useful in answering both functional and evo lutionary questions.