RESUMO
Here we report the cloning of zebrafish erm and pea3 cDNAs, which are members of the PEA3 subgroup of Ets transcription factors. The expression patterns of these two genes were examined during zebrafish embryogenesis. Maternal mRNAs of both genes are detectable and transcripts are found ubiquitously until the late blastula, in the marginal zone of gastrula stages and in the presumptive fore- and hindbrain and in the trunk region of early somite stages. Later, erm expression is observed in distinct regions of the forebrain, the mid-/hindbrain boundary, the differentiating rhombomeres, branchial arches, otic vesicles, the pectoral fins, the somites and the tailbud in a dynamic fashion. In contrast, pea3 is not expressed in the rhombomeres but in the Rohon-Beard neurons, the sensory lateral line placodes and the heart.
Assuntos
Encéfalo/embriologia , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição/genética , Peixe-Zebra/embriologia , Animais , Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Embrião não Mamífero , Olho/embriologia , Olho/metabolismo , Feminino , Coração/embriologia , Dados de Sequência Molecular , Neurônios/metabolismo , Prosencéfalo/embriologia , Prosencéfalo/metabolismo , Rombencéfalo/embriologia , Rombencéfalo/metabolismo , Fatores de Transcrição/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-ZebraRESUMO
We report the cloning of a cDNA encoding a Xenopus laevis Ets-type transcription factor. This new Xenopus gene belongs to the PEA3 subfamily of Ets proteins and shows the highest degree of sequence similarity to the mouse and human ER81 genes. The Xenopus ER81 gene (XER81) is transcribed in the embryo after mid blastula transition (MBT) and three transcripts of 3, 4 and 6 kb are detected throughout embryogenesis. XER81 mRNA is localized in the animal pole of the late blastula stage and higher levels of XER81 transcripts are detected in the marginal zone at the onset of gastrulation. In later embryogenesis XER81 transcripts are found in neural crest cells, eyes, otic vesicles and pronephros. The transcription of XER81 can be stimulated by bFGF and eFGF in animal and vegetal cap explants. Expression of the dominant negative FGF receptor mutant in animal caps and embryos blocks XER81 transcription, arguing that the expression of this Ets gene requires active FGF signaling. The spatial overlap of eFGF and XER81 expression domains supports the idea that XER81 transcription could be a marker for regions with active FGF signaling in the embryo.
