title: A nonsense mutation in zebrafish gata1 causes the bloodless phenotype in vlad tepes.
abstract: Vlad tepes (vlt(m651)) is one of only five "bloodless" zebrafish mutants isolated through large-scale chemical mutagenesis screening. It is characterized by a severe reduction in blood cell progenitors and few or no blood cells at the onset of circulation. We now report characterization of the mutant phenotype and the identification of the gene mutated in vlt(m651). Embryos homozygous for the vlt(m651) mutation had normal expression of hematopoietic stem cell markers through 24 h postfertilization, as well as normal expression of myeloid and lymphoid markers. Analysis of erythroid development revealed variable expression of erythroid markers. Through positional and candidate gene cloning approaches we identified a nonsense mutation in the gata1 gene, 1015C --> T (Arg-339 --> Stop), in vlt(m651). The nonsense mutation was located C-terminal to the two zinc fingers and resulted in a truncated protein that was unable to bind DNA or mediate GATA-specific transactivation. A BAC clone containing the zebrafish gata1 gene was able to rescue the bloodless phenotype in vlt(m651). These results show that the vlt(m651) mutation is a previously uncharacterized gata1 allele in the zebrafish. The vlt(m651) mutation sheds new light on Gata1 structure and function in vivo, demonstrates that Gata1 plays an essential role in zebrafish hematopoiesis with significant conservation of function between mammals and zebrafish, and offers a powerful tool for future studies of the hematopoietic pathway.
authors.affiliation: National Human Genome Research Institute, National Institutes of Health, Building 49, Room 3A18, Bethesda, MD 20892, USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Lyons
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Lawson
authors.forename: Lin
authors.initials: L
authors.lastname: Lei
authors.forename: Paul E
authors.initials: PE
authors.lastname: Bennett
authors.forename: Brant M
authors.initials: BM
authors.lastname: Weinstein
authors.forename: P Paul
authors.initials: PP
authors.lastname: Liu
mesh_terms: D016475:3T3 Cells; D000483:Alleles; D000818:Animals; D002503:Centromere; D018389:Codon, Nonsense; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D008040:Genetic Linkage; D005838:Genotype; D006720:Homozygote; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D015027:Zebrafish; D029961:Zebrafish Proteins
chemical_list: D018389:Codon, Nonsense; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; C494689:Gata1 protein, mouse; D014157:Transcription Factors; D029961:Zebrafish Proteins; C494691:gata1a protein, zebrafish; D004247:DNA