Restricted expression of the irreC-rst protein is required for normal axonal projections of columnar visual neurons.
The 104 kDa irreC-rst protein, a member of the immunoglobulin superfamily, mediates homophilic adhesion in cell cultures. In larval optic chiasms, the protein is found on recently formed axon bundles, not on older ones. In developing visual neuropils, it is present in all columnar domains of specific layers. The number of irreC-rst-positive neuropil stratifications increases until the midpupal stage. Immunoreactivity fades thereafter. The functional importance of the restricted expression pattern is demonstrated by the severe projection errors of axons in the first and second optic chiasms in loss of function mutants and in transformants that express the irreC-rst protein globally. Epigenesis of the phenotypes can be explained partially on the bases of homophilic irreC-rst interactions.
Schneider
T
T
Institut für Biologie III, Albert-Ludwigs-Universität Freiburg, Germany.
Reiter
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C
Eule
E
E
Bader
B
B
Lichte
B
B
Nie
Z
Z
Schimansky
T
T
Ramos
R G
RG
Fischbach
K F
KF
D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000502:physiology*; D002448:Cell Adhesion; D015816:Cell Adhesion Molecules, Neuronal / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D002449:Cell Aggregation; D002478:Cells, Cultured; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development*; D005136:Eye Proteins; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D006358:Hot Temperature; D007301:Insect Hormones / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D007814:Larva; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009897:Optic Chiasm / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D009899:Optic Lobe, Nonmammalian / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D011679:Pupa; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014162:Transfection; D014795:Visual Pathways / Q000254:growth & development*
D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; D005136:Eye Proteins; D007301:Insect Hormones; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; C051642:fasciclin II; C085209:rst protein, Drosophila