Kevin J. Mitchell

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The robo gene in Drosophila was identified in a large-scale mutant screen for genes that control the decision by axons to cross the CNS midline. In robo mutants, too many axons cross and recross the midline. Here we show that robo encodes an axon guidance receptor that defines a novel subfamily of immunoglobulin superfamily proteins that is highly conserved(More)
Two tandem Netrin genes in Drosophila are expressed at the midline of the developing CNS and in different subsets of neurons, muscles, and epidermal patches. In embryos carrying a small deficiency that deletes both genes, CNS axon commissures are partially missing or thinner. This phenotype is rescued by expressing either Netrin gene at the midline.(More)
We have identified a Drosophila member of the deleted in colorectal cancer (DCC) gene family. The frazzled gene encodes transmembrane proteins that contain four immunoglobulin C2 type domains, six fibronectin type III repeats, and a cytoplasmic domain of 278 amino acids. Like vertebrate members of the DCC family, Frazzled is expressed on axons in the(More)
The search to understand the mechanisms regulating brain wiring has relied on biochemical purification approaches in vertebrates and genetic approaches in invertebrates to identify molecular cues and receptors for axon guidance. Here we describe a phenotype-based gene-trap screen in mice designed for the large-scale identification of genes controlling the(More)
The molecular mechanisms controlling the ability of motor axons to recognize their appropriate muscle targets were dissected using Drosophila genetics to add or subtract Netrin A, Netrin B, Semaphorin II, and Fasciclin II alone or in combination. Fas II and Sema II are expressed by all muscles where they promote (Fas II) or inhibit (Sema II) promiscuous(More)
We describe the successful application of a modified gene-trap approach, the secretory trap, to systematically analyze the functions in vivo of large numbers of genes encoding secreted and membrane proteins. Secretory-trap insertions in embryonic stem cells can be transmitted to the germ line of mice with high efficiency and effectively mutate the target(More)
The term synaesthesia has been applied to a range of different sensory-perceptual and cognitive experiences, yet how these experiences are related to each other is not well understood. Not only are there disparate types of synaesthesia, but even within types there are vast individual differences in the way that stimuli induce synaesthesia and in the(More)
Synesthesia is a condition where stimulation of a single sensory modality or processing stream elicits an idiosyncratic, yet reliable perception in one or more other modalities or streams. Various models have been proposed to explain synesthesia, which have in common aberrant cross-activation of one cortical area by another. This has been observed directly(More)
Cell-cell signalling of semaphorin ligands through interaction with plexin receptors is important for the homeostasis and morphogenesis of many tissues and is widely studied for its role in neural connectivity, cancer, cell migration and immune responses. SEMA4D and Sema6A exemplify two diverse vertebrate, membrane-spanning semaphorin classes (4 and 6) that(More)
Hippocampal mossy fibers project preferentially to the stratum lucidum, the proximal-most lamina of the suprapyramidal region of CA3. The molecular mechanisms that govern this lamina-restricted projection are still unknown. We examined the projection pattern of mossy fibers in mutant mice for semaphorin receptors plexin-A2 and plexin-A4, and their ligand,(More)