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Mutation of the glass onion locus causes drastic neuronal patterning defects in the zebrafish retina and brain. The precise stratified appearance of the wild-type retina is absent in the mutants. The glass onion phenotype is first visible shortly after the formation of optic primordia and is characterized by the rounding of cells and disruption of the(More)
The vertebrate nervous system contains an immense diversity of distinct cellular components that are organized into precise spatial patterns. The importance of accurate neuronal architecture is particularly obvious in the retina, where it is necessary for the formation of visual images. The retina is structured in a distinct layered pattern that is(More)
Guidance of axons by molecular gradients is crucial for wiring up the developing nervous system. It often is assumed that the unique signature of such guidance is immediate and biased turning of the axon tip toward or away from the gradient. However, here we show that such turning is not required for guidance. Rather, by a combination of experimental and(More)
In this study we examine the spectral and morphometric properties of the four important lunar mare dome fields near Cauchy, Arago, Hortensius, and Milichius. We utilise Clementine UVVIS multispectral data to examine the soil composition of the mare domes while employing telescopic CCD imagery to compute digital elevation maps in order to determine their(More)
The zebrafish has been established as a mainstream research system, largely due to the immense success of genetic screens. Over 2000 mutant alleles affecting zebrafish's early development have been isolated in two large-scale morphological screens and several smaller efforts. So far, over 50 mutant strains display retinal defects and many more have been(More)
To gain an understanding of molecular events that underlie pattern formation in the retina, we evaluated the expression profiles of over 8000 transcripts randomly selected from an embryonic zebrafish library. Detailed analysis of cDNAs that display restricted expression patterns revealed factors that are specifically expressed in single cell classes and are(More)
Wiring up the nervous system depends on the precise guidance of axonal growth cones to their targets. A key mechanism underlying this guidance is chemotaxis, whereby growth cones detect and follow molecular gradients. Although recent work has uncovered many of the molecules involved in this process, the mechanisms underlying chemotactic axon guidance are(More)
Axon guidance by molecular gradients plays a crucial role in wiring up the nervous system. However, the mechanisms axons use to detect gradients are largely unknown. We first develop a Bayesian "ideal observer" analysis of gradient detection by axons, based on the hypothesis that a principal constraint on gradient detection is intrinsic receptor binding(More)
Axon guidance by molecular gradients plays a crucial role in wiring up the nervous system. However, the mechanisms axons use to detect gradients are largely unknown. We first develop a Bayesian ''ideal observer'' analysis of gradient detection by axons, based on the hypothesis that a principal constraint on gradient detection is intrinsic receptor binding(More)
The "pipette" or "growth cone turning" assay is widely used for studying how axons respond to diffusible guidance cues in their environment. However, little quantitative analysis has been presented of the gradient shapes produced by this assay, or how they depend on parameters of the assay. Here we used confocal microscopy of fluorescent gradients to(More)