title: Antifeeding properties of myosuppressin in a generalist phytophagous leafworm, Spodoptera littoralis (Boisduval).
abstract: Insect myosuppressins are a family of peptides with a characteristic HV/SFLRFamide carboxy terminus. They are expressed in brain, neurohemal organs, stomatogastric nervous system, and in midgut endocrine cells. From a functional point of view, myosuppressins inhibit contractions of different visceral muscles, stimulate certain skeletal muscles and activate enzyme secretion from the gut. Moreover, in the omnivorous cockroach Blattella germanica, myosuppressin inhibits food intake. Based on these results, we studied the antifeeding activity of myosuppressin in the phytophagous leafworm Spodoptera littoralis. Firstly, we isolated the cDNA corresponding to the S. littoralis myosuppressin precursor encoding the typical myosuppressin peptide of lepidopterans: pQDVVHSFLRFamide. Then, we determined the expression patterns (in terms of mRNA and peptide) of myosuppressin in brain and midgut, and peptide levels in the haemolymph. Myosuppressin patterns in the brain and haemolymph were similar, and symmetrical to that of food consumption, thus suggesting that myosuppressin might inhibit feeding in S. littoralis. Moreover, synthetic myosuppressin effectively inhibited food intake in non-choice antifeeding tests. Taken together, the obtained results point to the hypothesis that myosuppressin represses feeding in S. littoralis.
authors: Department of Physiology and Molecular Biodiversity, Institut de Biologia Molecular de Barcelona (CSIC), Jordi Girona, 18-26, 08034 Barcelona, Spain.
authors: Lluïsa
authors: L
authors: Vilaplana
authors: Nuria
authors: N
authors: Pascual
authors: Nathalia
authors: N
authors: Perera
authors: Daniel
authors: D
authors: Leira
authors: Xavier
authors: X
authors: Bellés
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D004797:Enzyme-Linked Immunosorbent Assay; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D018411:Spodoptera / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D009479:Neuropeptides; D012333:RNA, Messenger