title: Molecular characterization and immunological response analysis of a novel  transferrin-like, pacifastin heavy chain protein in giant freshwater prawn,  Macrobrachium rosenbergii (De Man, 1879).
abstract: The full-length cDNA of the pacifastin heavy chain gene from giant freshwater prawn (Macrobrachium rosenbergii, Mr-PHC) was cloned and characterized. The full sequence of the Mr-PHC cDNA was 4331 bp and contained a 119-bp 5'-untranslated region (UTR), a 3990-bp open reading frame (ORF) encoding 1329 amino acid residues and a 222-bp 3' UTR. The Mr-PHC protein predicted by its full ORF, exhibited a unique transferrin-like protein structure containing 4 different lobes that have not been previously identified. Three of the four lobes contained highly conserved of iron/anion binding residues. Expression analyses by conventional RT-PCR demonstrated that Mr-PHC was expressed predominantly during postlarval stage 45 and also in the foregut and gills of the adult prawn. Interestingly, dose response analyses that were quantified using quantitative real-time PCR indicated a significant upregulation of Mr-PHC during postlarval stage 45 in prawn grown at hour 24 after challenging with 10(9) cfu/ml of Aeromonas hydrophila, which is a pathogenic bacterium. Mr-HPC in the adult prawn was significantly upregulated at both hour 12 and day 7 after stimulation with A. hydrophila (P < 0.05 and P < 0.01, respectively). Additionally, a delayed induction response of the Mr-PHC gene was observed at 14 days when the experimental adult prawns were fed with β-glucan-supplemented feed. Based on results of this study, the transferrin-like protein encoded by the pacifastin heavy chain gene may exist in all decapod crustaceans. Even though the function as an iron transporter is not proven, immune response studies are clearly indicated that PHC is critically involved in the immune system in these animals.
authors.affiliation: Laboratory of Aquatic Animal Health Management, Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Aung
authors.initials: A
authors.lastname: Toe
authors.forename: Nontawith
authors.initials: N
authors.lastname: Areechon
authors.forename: Prapansak
authors.initials: P
authors.lastname: Srisapoome
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology; D000595:Amino Acid Sequence; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling / Q000662:veterinary; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D033541:Palaemonidae / Q000235:genetics / Q000254:growth & development / Q000276:immunology* / Q000382:microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment / Q000662:veterinary; D017385:Sequence Homology; D014168:Transferrin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D047071:beta-Glucans / Q000276:immunology
chemical_list: D018076:DNA, Complementary; D011506:Proteins; D012333:RNA, Messenger; D014168:Transferrin; D047071:beta-Glucans; C106709:pacifastin