title: Developmental expression and organisation of fibrinogen genes in the zebrafish.
abstract: The zebrafish is a model organism for studying vertebrate development and many human diseases. Orthologues of the majority of human coagulation factors are present in zebrafish, including fibrinogen. As a first step towards using zebrafish to model human fibrinogen disorders, we cloned the zebrafish fibrinogen cDNAs and made in situ hybridisations and quantitative reverse transcription-polymerase chain reactions (qRT-PCR) to detect zebrafish fibrinogen mRNAs. Prior to liver development or blood flow we detected zebrafish fibrinogen expression in the embryonic yolk syncytial layer and then in the early cells of the developing liver. While human fibrinogen is encoded by a three-gene, 50 kilobase (kb) cluster on chromosome 4 ( FGB-FGA-FGG ), recent genome assemblies showed that the zebrafish  fgg  gene appears distanced from  fga  and  fgb , which we confirmed by in situ hybridisation. The zebrafish fibrinogen Bβ and γ protein chains are conserved at over 50% of amino acid positions, compared to the human polypeptides. The zebrafish Aα chain is less conserved and its C-terminal region is nearly 200 amino acids shorter than human Aα. We generated transgenic zebrafish which express a green fluorescent protein reporter gene under the control of a 1.6 kb regulatory region from zebrafish  fgg . Transgenic embryos showed strong fluorescence in the developing liver, mimicking endogenous fibrinogen expression. This regulatory sequence can now be used for overexpression of transgenes in zebrafish hepatocytes. Our study is a proof-of-concept step towards using zebrafish to model human disease linked to fibrinogen gene mutations.
authors: Department of Genetic Medicine and Development, University of Geneva Medical Centre, 1, rue Michel-Servet, 1211 Geneva 4, Switzerland. Richard.Fish@unige.ch
authors: Richard J
authors: RJ
authors: Fish
authors: Silja
authors: S
authors: Vorjohann
authors: Frédérique
authors: F
authors: Béna
authors: Alexandre
authors: A
authors: Fort
authors: Marguerite
authors: M
authors: Neerman-Arbez
mesh_terms: D000818:Animals; D002460:Cell Line; D018076:DNA, Complementary / Q000378:metabolism; D005340:Fibrinogen / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology; D006801:Humans; D017403:In Situ Hybridization; D017404:In Situ Hybridization, Fluorescence; D008957:Models, Genetic; D005810:Multigene Family; D009154:Mutation; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D019076:Transgenes; D015027:Zebrafish
chemical_list: D018076:DNA, Complementary; D049452:Green Fluorescent Proteins; D005340:Fibrinogen