Slit is the midline repellent for the robo receptor in Drosophila.
Previous studies suggested that Roundabout (Robo) is a repulsive guidance receptor on growth cones that binds to an unknown midline ligand. Here we present genetic evidence that Slit is the midline Robo ligand; a companion paper presents biochemical evidence that Slit binds Robo. Slit is a large extracellular matrix protein expressed by midline glia. In slit mutants, growth cones enter the midline but never leave it; they abnormally continue to express high levels of Robo while at the midline. slit and robo display dosage-sensitive genetic interactions, indicating that they function in the same pathway. slit is also required for migration of muscle precursors away from the midline. Slit appears to function as a short-range repellent controlling axon crossing of the midline and as a long-range chemorepellent controlling mesoderm migration away from the midline.
Kidd
T
T
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Bland
K S
KS
Goodman
C S
CS
D000818:Animals; D001369:Axons / Q000502:physiology; D001483:Base Sequence; D019521:Body Patterning; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames; D010641:Phenotype; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D000097905:Roundabout Proteins
D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; D008024:Ligands; D009419:Nerve Tissue Proteins; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; C066819:sli protein, Drosophila