Asymmetric Notch activation specifies photoreceptors R3 and R4 and planar polarity in the Drosophila eye

Manolis Fanto and Marek Mlodzik ()
Additional contact information
Manolis Fanto: Developmental Biology Programme, EMBL
Marek Mlodzik: Developmental Biology Programme, EMBL

Nature, 1999, vol. 397, issue 6719, 523-526

Abstract: Abstract Planar polarity is seen in epidermally derived structures throughout the animal kingdom1,2. In the Drosophila eye, planar polarity is reflected in the mirror-symmetric arrangement of ommatidia (eye units) across the dorsoventral midline or equator; ommatidia on the dorsal and ventral sides of the equator exhibit opposite chirality3,4,5. Photoreceptors R3 and R4 are essential in the establishment of the polarity of ommatidia6,7,8,9,10,11. The R3 cell is thought to receive the polarizing signal, through the receptor Frizzled (Fz), before or at higher levels then the R4 cell, generating a difference between neighbouring R3 and R4 cells6,7,9,10. Both loss-of-function and overexpression of Fz in the R3/R4 pair result in polarity defects and loss of mirror-image symmetry6,7,9,10,12. Here we identify Notch and Delta (Dl) as dominant enhancers of the phenotypes produced by overexpression of fz and dishevelled (dsh), which encodes a signalling component downstream of Fz, and we show that Dl-mediated activation of Notch is required for establishment of ommatidial polarity. Whereas fz signalling is required to specify R3, Notch signalling induces the R4 fate. Our data indicate that Dl is a transcriptional target of Fz/Dsh signalling in R3, and activates Notch in the neighbouring R4 precursor. This two-tiered mechanism explains how small differences in the level and/or timing of Fz activation reliably generate a binary cell-fate decision, leading to specification of R3 and R4 and ommatidial chirality.

Date: 1999
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/17389 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:397:y:1999:i:6719:d:10.1038_17389

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/17389

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().