Subject(s)
Atrial Natriuretic Factor/genetics , Heart/growth & development , Animals , Animals, Genetically Modified , Binding Sites/genetics , Drosophila/genetics , Drosophila/growth & development , Gene Expression Regulation, Developmental , Heart/embryology , Models, Cardiovascular , Promoter Regions, Genetic , VertebratesABSTRACT
We have isolated and characterized the developmental expression of the Xenopus Iroquois 4 (Irx4) and Iroquois 5 (Irx5) homeodomain transcription factors. Irx4 is expressed in a subset of cells in the neural retina and the developing hindbrain and also, specifically, in the ventricle of the heart. Xenopus Irx5 is expressed in the developing midbrain, hindbrain, neural tube, and also in the retina.
Subject(s)
Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Transcription Factors/genetics , Xenopus Proteins , Amino Acid Sequence , Animals , Brain/embryology , Brain/metabolism , Conserved Sequence , Heart/embryology , Homeodomain Proteins/physiology , Humans , Molecular Sequence Data , Myocardium/metabolism , Retina/embryology , Retina/metabolism , Sequence Homology, Amino Acid , Transcription Factors/physiology , Xenopus , Zebrafish , Zebrafish ProteinsABSTRACT
The homeodomain transcription factor Nkx2-1 (TTF-1) plays an essential role in the development of the thyroid, lung and ventral forebrain. We report the cloning and developmental expression patterns of two Xenopus NK-2 genes, Nkx2-1 and Nkx2-4, that are closely related to Nkx2-1. These genes show readily distinguishable expression patterns during development. Similar to its orthologues in chicken and mouse, the Xenopus Nkx2-1 gene is expressed in the developing thyroid, lung, and ventral forebrain. In contrast, expression of Nkx2-4 is specifically localized to the ventral diencephalon.
Subject(s)
Homeodomain Proteins/genetics , Nuclear Proteins/genetics , Transcription Factors/genetics , Xenopus Proteins , Xenopus/embryology , Xenopus/genetics , Amino Acid Sequence , Animals , Chick Embryo , Gene Expression Regulation, Developmental , In Situ Hybridization , Lung/embryology , Mice , Molecular Sequence Data , Prosencephalon/embryology , Sequence Homology, Amino Acid , Thyroid Gland/embryology , Thyroid Nuclear Factor 1ABSTRACT
We have isolated the Xenopus orthologue of the atrial natriuretic factor (ANF) gene. Characterization of embryonic expression indicates that the ANF gene is initially expressed throughout the developing myocardium at the late heart tube stage (about stage 32). This is in contrast to all previously characterized Xenopus cardiac differentiation markers that are first expressed in the cardiogenic plate at approximately stage 27. ANF expression becomes restricted exclusively to the atrium at about stage 47, long after the commencement of beating and the original formation of the atrial and ventricular compartments, but shortly after septation of the single atrium into two distinct atria.
