Deborah Yelon

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The precursors of several organs reside within the lateral plate mesoderm of vertebrate embryos. Here, we demonstrate that the zebrafish hands off locus is essential for the development of two structures derived from the lateral plate mesoderm - the heart and the pectoral fin. hands off mutant embryos have defects in myocardial development from an early(More)
Organ progenitors arise within organ fields, embryonic territories that are larger than the regions required for organ formation. Little is known about the regulatory pathways that define organ field boundaries and thereby limit organ size. Here we identify a mechanism for restricting heart size through confinement of the developmental potential of the(More)
The embryonic vertebrate heart is divided into two major chambers, an anterior ventricle and a posterior atrium. Although the fundamental differences between ventricular and atrial tissues are well documented, it is not known when and how cardiac anterior-posterior (A-P) patterning occurs. The expression patterns of two zebrafish cardiac myosin genes,(More)
A conserved endothelin 1 signaling pathway patterns the jaw and other pharyngeal skeletal elements in mice, chicks and zebrafish. In zebrafish, endothelin 1 (edn1 or sucker) is required for formation of ventral cartilages and joints in the anterior pharyngeal arches of young larvae. Here we present genetic analyses in the zebrafish of two edn1 downstream(More)
How adjacent organ fields communicate during development is not understood. Here, we identify a mechanism in which signaling within the forelimb field restricts the potential of the neighboring heart field. In zebrafish embryos deficient in retinoic acid (RA) signaling, the pectoral fins (forelimbs) are lost while both chambers of the heart are enlarged. We(More)
The mechanisms regulating vertebrate heart and endoderm development have recently become the focus of intense study. Here we present evidence from both loss- and gain-of-function experiments that the zinc finger transcription factor Gata5 is an essential regulator of multiple aspects of heart and endoderm development. We demonstrate that zebrafish Gata5 is(More)
Natural models of heart regeneration in lower vertebrates such as zebrafish are based on invasive surgeries causing mechanical injuries that are limited in size. Here, we created a genetic cell ablation model in zebrafish that facilitates inducible destruction of a high percentage of cardiomyocytes. Cell-specific depletion of over 60% of the ventricular(More)
Developing organs acquire a specific three-dimensional form that ensures their normal function. Cardiac function, for example, depends upon properly shaped chambers that emerge from a primitive heart tube. The cellular mechanisms that control chamber shape are not yet understood. Here, we demonstrate that chamber morphology develops via changes in cell(More)
Early endoderm formation in zebrafish requires at least three loci that function downstream of Nodal signaling but upstream of the early endodermal marker sox17: bonnie and clyde (bon), faust (fau), and casanova (cas). cas mutants show the most severe phenotype as they do not form any gut tissue and lack all sox17 expression. Activation of the Nodal(More)
Vertebrate endoderm development has recently become the focus of intense investigation. In this report, we first show that the zebrafish bonnie and clyde (bon) gene plays a critical early role in endoderm formation. bon mutants exhibit a profound reduction in the number of sox17-expressing endodermal precursors formed during gastrulation, and, consequently,(More)