Scabrous overexpression in the eye affects R3/R4 cell fate specification and inhibits notch signaling.
BACKGROUND
Planar cell polarity (PCP) in the Drosophila eye is generated when immature ommatidial preclusters acquire opposite chirality in the dorsal and ventral halves of the eye imaginal disc and rotate 90 ° toward the equator. The scabrous (sca) gene is involved in R8 differentiation and in the correct spacing of ommatidial clusters in eye imaginal discs, but it was also suggested to be required during ommatidial rotation. However, no clear relationships between sca and other genes involved in the process were established.


RESULTS
To explore the role of Sca in PCP establishment, we performed an RNAi-based modifier genetic screen using the rough eye phenotype of sca-overexpressing flies. We found that sca overexpression mainly affects R3/R4 cell specification as it was reported in Notch mutants. Of the 86 modifiers identified in the screen, genes encoding components of Notch signaling and proteins involved in intracellular transport were of particular interest.


CONCLUSIONS
These and other results obtained with a reporter line of Notch activity indicate that sca overexpression antagonizes Notch signaling in the Drosophila eye, and are inconsistent with Sca being an ommatidial rotation-specific factor. We also found that microtubule motors and other proteins involved in intracellular transport are related with Sca function.
['Muñoz-Soriano|Verónica|V|', 'Santos|Diego|D|', 'Durupt|Fabrice C|FC|', 'Casani|Sandra|S|', 'Paricio|Nuria|N|']
D000818:Animals D030801:Animals, Genetically Modified D002454:Cell Differentiation D019070:Cell Lineage D054910:Compound Eye, Arthropod D029721:Drosophila Proteins D004331:Drosophila melanogaster D006023:Glycoproteins D010641:Phenotype D051880:Receptors, Notch D015398:Signal Transduction
planar cell polarity Drosophila genetic screen dominant modifiers intracellular trafficking symmetrical ommatidia