title: Expression of a cystine-rich fish antifreeze in transgenic Drosophila melanogaster.
abstract: We have used Drosophila melanogaster as a model system for the transgenic expression of cystine-rich Type II antifreeze protein (AFP) from sea raven. This protein was synthesized and secreted into fly haemolymph where it migrated as a larger species (16 kDa) than the mature form of the protein (14 kDa) as judged by immunoblotting. Drosophila-produced Type II AFP demonstrated antifreeze activity both in terms of thermal hysteresis (0.13 degree C) and inhibition of ice recrystallization. Recombinant AFP was purified and N-terminal sequencing revealed a 17 aa extension that began at the predicted signal peptide cleavage point. The expression of all three AFP types in transgenic Drosophila has now been achieved. We conclude that the globular Type II and Type III AFPs are better choices for antifreeze transfer to other organisms than is the more widely used linear Type I AFP.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada.
authors.forename: B P
authors.initials: BP
authors.lastname: Duncker
authors.forename: J A
authors.initials: JA
authors.lastname: Hermans
authors.forename: P L
authors.initials: PL
authors.lastname: Davies
authors.forename: V K
authors.initials: VK
authors.lastname: Walker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D021341:Antifreeze Proteins, Type II; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D003460:Crystallization; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D006458:Hemolymph / Q000737:chemistry / Q000378:metabolism; D007053:Ice; D008297:Male; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics
chemical_list: D021341:Antifreeze Proteins, Type II; D002352:Carrier Proteins; D007053:Ice; D011498:Protein Precursors; C089666:antifreeze protein, sea raven