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Pax6 and Pax2 are members of the Pax family of transcription factors that are both expressed in the developing visual system of zebrafish embryos. Pax6 protein is present in all cells that form the neural retina and pigment epithelium, whereas Pax2 is located primarily in cells that will give rise to the optic stalk. In this study, we have addressed the(More)
During development of the zebrafish forebrain, a simple scaffold of axon pathways is pioneered by a small number of neurons. We show that boundaries of expression domains of members of the eph, forkhead, pax, and wnt gene families correlate with the positions at which these neurons differentiate and extend axons. Analysis of genetically or experimentally(More)
During development of the vertebrate hindbrain regulatory gene expression is confined to precise segmental domains. Studies of cell lineage and gene expression suggest that establishment of these domains may involve a dynamic regulation of cell identity and restriction of cell movement between segments. We have taken a dominant negative approach to(More)
A number of studies have suggested that retinoic acid (RA) is an important signal for patterning the hindbrain, the branchial arches and the limb bud. Retinoic acid is thought to act on the posterior hindbrain and the limb buds at somitogenesis stages in chick and mouse embryos. Here we report a much earlier requirement for RA signalling during(More)
No-isthmus (Noi) is a member of the zebrafish Pax family of transcriptional regulators that is expressed in restricted domains of the developing CNS. In the developing eye and optic nerve, the Noi+ cells are primitive glial cells that line the choroid fissure and optic stalk/nerve to its junction with the optic tract. This pattern of Noi expression is(More)
The isolation and characterisation of two zebrafish Eph receptor ligand cDNAs which we have called zfEphL3 and zfEphL4 is described. These genes are expressed in the presumptive midbrain of developing embryos from 6 somites. By 24 hours L3 is expressed throughout the midbrain including the region of the presumptive tectum whereas L4 is strongly expressed in(More)
  • N Holder
  • 1983
The skeletal makeup of the digits of 145 hands and feet from species from the four classes of tetrapod vertebrates is analysed. The analysis leads to the conclusion that developmental constraints are very influential in the evolution of vertebrate digit patterns. Furthermore, 98% of the patterns analysed fall within the specific constraints of the Stock &(More)
The numbers and positions of cells undergoing cell death and proliferation in the neuromasts of 10 day old zebrafish larvae were assessed to investigate the ability of supporting cells to differentiate into hair cells. Evaluations of cell death and proliferation showed that a subpopulation of cells located in the centre of the neuromast undergo cell death,(More)
Considerable evidence now suggests that retinoic acid (RA) is an important modulator of patterning events in early neuronal development in vertebrates. In this paper, we describe the effects of exogenously applied RA on early neural development in the zebrafish embryo. Neural anatomy is assessed by immunocytochemical and histochemical analysis of the(More)
We describe the isolation and early developmental expression of three novel zebrafish genes (rtk1-3) that encode members of the eph family of receptor tyrosine kinases. At the onset of gastrulation, rtk1 is expressed in the shield region corresponding to the future dorsal side of the embryo. As gastrulation proceeds, both rtk1 and rtk2 are expressed within(More)