Proteomic analysis of buccal gland secretion from fasting and feeding lampreys ( Lampetra morii ).

Background: Previous studies have shown that lamprey buccal glands contain some regulators related to anticoagulation, nociception, and immune responses due to the blood sucking habit. Regrettably, the protein expression profile in the buccal glands of feeding lampreys has never been reported yet. The present study was performed in order to further identify more proteins which are closely associated with lamprey feeding process.

Methods: 2D-PAGE, NanoLC-MS/MS with higher resolution, Ensembl lamprey and NCBI protein databases, as well as western blot was used to compare the proteomics of buccal gland secretion from China northeast lampreys ( Lampetra morii ) which had been fed for 0, 10, and 60 min, respectively.

Results: In the present study, the number of identified protein species in the buccal glands of feeding groups (60 min) was increased significantly, nearly ten times of that in the fasting group. During the feeding stage, novel proteins emerged in the buccal gland secretion of lampreys. According to gene ontology (GO) analysis and function predictions, these proteins were summarized and discussed based on their potential roles during feeding process. Furthermore, some of the identified proteins were confirmed to express during the feeding time of lampreys.

Conclusion: When lampreys attack host fishes to suck blood and flesh, their buccal glands could secrete enough proteins to suppress blood coagulation, nociception, oxidative stress, immune response, as well as other adverse effects encountered during their parasitic lives. The present study would provide clues to clarify the feeding mechanism of the bloodsucking lampreys.