title: Structure and expression of transferrin gene of channel catfish, Ictalurus punctatus.
abstract: Transferrin is important in iron metabolism and has been reported to be involved in disease defence responses after bacterial infection. In this study, we identified, sequenced, and characterized the transferrin gene from channel catfish, Ictalurus punctatus. The catfish transferrin gene was similar to those of other vertebrate species with 17 exons and 16 introns. Sequence analysis indicated the presence of the two duplicated lobes, each containing two sub-domains separated by a cleft harboring the iron-binding site, suggesting their structural conservation. The channel catfish transferrin cDNA encodes 679 amino acids with 42-56% similarity to known transferrin genes from various species. Southern blot analysis suggested the presence of two copies of the transferrin gene in the catfish genome, perhaps arranged in a tandem fashion. The catfish transferrin gene was mapped to a catfish BAC-based physical map. The catfish transferrin gene was highly expressed in the liver, but expression was low in most other tested tissues. Transferrin expression was significantly up-regulated after infection with Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish. Such induction was also found with co-injection of iron-dextran and E. ictaluri, while transferrin expression was not significantly induced with the injection of iron-dextran alone.
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures, Aquatic Genomics Unit, Auburn University, Auburn, AL 36849, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Takano
authors.forename: Jason
authors.initials: J
authors.lastname: Abernathy
authors.forename: Shaolin
authors.initials: S
authors.lastname: Wang
authors.forename: Zhenxia
authors.initials: Z
authors.lastname: Sha
authors.forename: Yanliang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Jeffery
authors.initials: J
authors.lastname: Terhune
authors.forename: Huseyin
authors.initials: H
authors.lastname: Kucuktas
authors.forename: Eric
authors.initials: E
authors.lastname: Peatman
authors.forename: Zhanjiang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D015870:Gene Expression / Q000235:genetics; D005796:Genes / Q000235:genetics; D007059:Ictaluridae / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014168:Transferrin / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D014168:Transferrin