Thomas M. Schultheiss

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Despite recent advances in delineating the mechanisms involved in cardiogenesis, cellular lineage specification remains incompletely understood. To explore the relationship between developmental fate and potential, we isolated a cardiac-specific Nkx2.5(+) cell population from the developing mouse embryo. The majority of these cells differentiated into(More)
Formation of kidney tissue requires the generation of kidney precursor cells and their subsequent differentiation into nephrons, the functional filtration unit of the kidney. Here we report that the gene odd-skipped related 1 (Odd1) plays an important role in both these processes. Odd1 is the earliest known marker of the intermediate mesoderm, the precursor(More)
Little is known about the molecular mechanisms that govern heart specification in vertebrates. Here we demonstrate that bone morphogenetic protein (BMP) signaling plays a central role in the induction of cardiac myogenesis in the chick embryo. At the time when chick precardiac cells become committed to the cardiac muscle lineage, they are in contact with(More)
An experimental system was devised to study the mechanisms by which cells become committed to the cardiac myocyte lineage during avian development. Chick tissues from outside the fate map of the heart (in the posterior primitive streak (PPS) of a Hamburger & Hamilton stage 4 embryo) were combined with potential inducing tissues from quail embryos and(More)
A novel gene, Xin, from chick (cXin) and mouse (mXin) embryonic hearts, may be required for cardiac morphogenesis and looping. Both cloned cDNAs have a single open reading frame, encoding proteins with 2,562 and 1,677 amino acids for cXin and mXin, respectively. The derived amino acid sequences share 46% similarity. The overall domain structures of the(More)
The avian heart develops from paired primordia located in the anterior lateral mesoderm of the early embryo. Previous studies have found that the endoderm adjacent to the cardiac primordia plays an important role in heart specification. The current study provides evidence that fibroblast growth factor (Fgf) signaling contributes to the heart-inducing(More)
Heterozygous mutations of the cardiac transcription factor Nkx2-5 cause atrioventricular conduction defects in humans by unknown mechanisms. We show in KO mice that the number of cells in the cardiac conduction system is directly related to Nkx2-5 gene dosage. Null mutant embryos appear to lack the primordium of the atrioventricular node. In Nkx2-5(More)
The intermediate mesoderm lies between the somites and the lateral plate and is the source of all kidney tissue in the developing vertebrate embryo. While bone morphogenetic protein (Bmp) signaling is known to regulate mesodermal cell type determination along the medio-lateral axis, its role in intermediate mesoderm formation has not been well(More)
Amniote kidney tissue is derived from the intermediate mesoderm (IM), a strip of mesoderm that lies between the somites and the lateral plate. While much has been learned concerning the later events which regulate the differentiation of IM into tubules and other types of kidney tissue, much less is known concerning the earlier events which regulate(More)
The vertebrate intermediate mesoderm (IM) is highly patterned along the anterior-posterior (A-P) axis. In the chick embryo, the kidney tissue, which is a derivative of the IM, is generated only from IM located posterior to the sixth somite axial level, which also marks the border between cranial and trunk segments. The cellular and molecular mechanisms that(More)