title: Cloning and developmental expression of zebrafish GTP cyclohydrolase I.
abstract: GTP cyclohydrolase I (GCH) catalyses the conversion of GTP to dihydroneopterin triphosphate, initiating the pteridine pathway. The final product tetrahydrobiopterin (H4biopterin) is the cofactor for neurotransmitter synthesis and for tyrosine supply during melanogenesis. Sepiapterin accumulates as a pigment. We cloned the zebrafish gch cDNA, which encodes a protein highly homologous to other vertebrate sequences and characterised the recombinant enzyme. By in situ hybridisation, we found that gch is expressed in both the melanophore and xanthophore lineages during early development. gch-expression almost disappears after 3 days post-fertilisation (dpf), despite further sepiapterin synthesis. gch-transcripts are also located in catecholaminergic neurons, within the central nervous system and in the arch-associated neurons.
authors.affiliation: GSF-Research Centre for Environment and Health, Institute for Clinical Molecular Biology and Tumor Genetics, Munich, Germany. pelletier@gsf.de
authors.forename: I
authors.initials: I
authors.lastname: Pelletier
authors.forename: L
authors.initials: L
authors.lastname: Bally-Cuif
authors.forename: I
authors.initials: I
authors.lastname: Ziegler
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002395:Catecholamines / Q000378:metabolism; D019070:Cell Lineage; D002465:Cell Movement; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary; D006136:GTP Cyclohydrolase / Q000235:genetics*; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008547:Melanophores; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000166:cytology / Q000201:enzymology; D009474:Neurons / Q000201:enzymology; D012249:Rhombencephalon / Q000201:enzymology / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development
chemical_list: D002395:Catecholamines; D018076:DNA, Complementary; D006136:GTP Cyclohydrolase