title: Fatty acid solubilizer from the oral disk of the blowfly.
abstract: BACKGROUND
  Blowflies are economic pests of the wool industry and potential vectors for epidemics. The establishment of a pesticide-free, environmentally friendly blowfly control strategy is necessary. Blowflies must feed on meat in order to initiate the cascade of events that are involved in reproduction including juvenile hormone synthesis, vitellogenesis, and mating. During feeding blowflies regurgitate salivary lipase, which may play a role in releasing fatty acids from triglycerides that are found in food. However, long-chain fatty acids show low solubility in aqueous solutions. In order to solubilize and ingest the released hydrophobic fatty acids, the blowflies must use a solubilizer.
  
  
  METHODS
  We applied native PAGE, Edman degradation, cDNA cloning, and RT-PCR to characterize a protein that accumulated in the oral disk of the black blowfly, Phormia regina. In situ hybridization was carried out to localize the expression at the cellular level. A fluorescence competitive binding assay was used to identify potential ligands of this protein.
  
  
  CONCLUSIONS
  A protein newly identified from P. regina (PregOBP56a) belonged to the classic odorant-binding protein (OBP) family. This gene was expressed in a cluster of cells that was localized between pseudotracheae on the oral disk, which are not accessory cells of the taste peg chemosensory sensilla that normally synthesize OBPs. At pH 7 and pH 6, PregOBP56a bound palmitic, stearic, oleic, and linoleic acids, that are mainly found in chicken meat. The binding affinity of PregOBP56a decreased at pH 5. We propose that PregOBP56a is a protein that solubilizes fatty acids during feeding and subsequently helps to deliver the fatty acids to the midgut where it may help in the process of reproduction. As such, PregOBP56a is a potential molecular target for controlling the blowfly.
authors: Department of Biology, Graduate School of Science, Kobe University, Nada, Kobe, Hyogo, Japan. y-ishida@pu-toyama.ac.jp
authors: Yuko
authors: Y
authors: Ishida
authors: Jun
authors: J
authors: Ishibashi
authors: Walter S
authors: WS
authors: Leal
mesh_terms: D000595:Amino Acid Sequence; D000825:Animal Structures / Q000378:metabolism; D000818:Animals; D002645:Chickens; D002942:Circular Dichroism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004175:Diptera / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D050556:Fatty Acid-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008041:Linoleic Acids / Q000378:metabolism; D008460:Meat; D008969:Molecular Sequence Data; D019301:Oleic Acid / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism; D011485:Protein Binding; D018035:Receptors, Odorant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013229:Stearic Acids / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D019476:Insect Proteins; D008041:Linoleic Acids; D018035:Receptors, Odorant; D013229:Stearic Acids; C045648:odorant-binding protein; D019301:Oleic Acid; D019308:Palmitic Acid; C031183:stearic acid