title: Chemosensory proteins, major salivary factors in caterpillar mandibular glands.
abstract: Research in the field of insect-host plant interactions has indicated that constituents of insect saliva play an important role in digestion and affect host chemical defense responses. However, most efforts have focused on studying the composition and function of regurgitant or saliva produced in the labial glands. Acknowledging the need for understanding the role of the mandibular glands in herbivory, we sought to make a qualitative and semi-quantitative comparison of soluble luminal protein fractions between mandibular and labial glands of Vanessa gonerilla butterfly larvae. Amylase and lysozyme were inspected as possible major enzymatic activities in the mandibular glands aiding in pre-digestion and antimicrobial defense. Although detected, neither of these enzymatic activities was prominent in the luminal protein preparation of a particular type of gland. Proteins isolated from the glands were identified by mass spectrometry and by searching an EST-library database generated for four other nymphalid butterfly species, in addition to the public NCBI database. The identified proteins were also quantified from the data using "Quanty", an in-house program. The proteomic analysis detected chemosensory proteins as the most abundant luminal proteins in the mandibular glands. In comparison to these proteins, the relative amounts of amylase and lysozyme were much lower in both gland types. Therefore, we speculate that the primary role of the mandibular glands in Lepidopteran larvae is chemoreception which may include the detection of microorganisms on plant surfaces, host plant recognition and communication with conspecifics.
authors.affiliation: Stockholm University, Department of Zoology, Svante Arrheniusväg 18 B, 106 91, Stockholm, Sweden. maria.celorio@zoologi.su.se
authors.forename: Maria de la Paz
authors.initials: Mde L
authors.lastname: Celorio-Mancera
authors.forename: Sara M
authors.initials: SM
authors.lastname: Sundmalm
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.forename: Dorothea
authors.initials: D
authors.lastname: Rutishauser
authors.forename: A Jimmy
authors.initials: AJ
authors.lastname: Ytterberg
authors.forename: Roman A
authors.initials: RA
authors.lastname: Zubarev
authors.forename: Niklas
authors.initials: N
authors.lastname: Janz
mesh_terms: D000818:Animals; D002080:Butterflies / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D040901:Proteomics; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D013363:Submandibular Gland / Q000737:chemistry / Q000378:metabolism
chemical_list: D019476:Insect Proteins