Drosophila atonal controls photoreceptor R8-specific properties and modulates both receptor tyrosine kinase and Hedgehog signalling.
During Drosophila eye development, the proneural gene atonal specifies founding R8 photoreceptors of individual ommatidia, evenly spaced relative to one another in a pattern that prefigures ommatidial organisation in the mature compound eye. Beyond providing neural competence, however, it has remained unclear to what extent atonal controls specific R8 properties. We show here that reduced Atonal function gives rise to R8 photoreceptors that are functionally compromised: both recruitment and axon pathfinding defects are evident. Conversely, prolonged Atonal expression in R8 photoreceptors induces defects in inductive recruitment as a consequence of hyperactive EGFR signalling. Surprisingly, such prolonged expression also results in R8 pattern formation defects in a process associated with both Hedgehog and Receptor Tyrosine Kinase signalling. Our results strongly suggest that Atonal regulates signalling and other properties of R8 precursors.
White
N M
NM
Institute of Cell and Molecular Biology, University of Edinburgh, King's Buildings, Edinburgh, EH9 3JR, UK.
Jarman
A P
AP
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D066246:ErbB Receptors / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D053823:Hedgehog Proteins; D018257:Helix-Loop-Helix Motifs; D019476:Insect Proteins / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D016296:Mutagenesis; D009419:Nerve Tissue Proteins; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D066246:ErbB Receptors; D005136:Eye Proteins; D053823:Hedgehog Proteins; D019476:Insect Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D020794:Receptor Protein-Tyrosine Kinases; C082142:ato protein, Drosophila; C077245:hh protein, Drosophila; C056737:sev protein, Drosophila