Reference Report

Reference
Citation	Pappu, K.S., Morey, M., Nern, A., Spitzweck, B., Dickson, B.J., Zipursky, S.L. (2011). Robo-3-mediated repulsive interactions guide R8 axons during Drosophila visual system development. Proc. Natl. Acad. Sci. U.S.A. 108(18): 7571--7576. (Export to RIS)
FlyBase ID	FBrf0213605
Publication Type	Research paper
PubMed ID	21490297
PubMed Abstract	The formation of neuronal connections requires the precise guidance of developing axons toward their targets. In the Drosophila visual system, photoreceptor neurons (R cells) project from the eye into the brain. These cells are grouped into some 750 clusters comprised of eight photoreceptors or R cells each. R cells fall into three classes: R1 to R6, R7, and R8. Posterior R8 cells are the first to project axons into the brain. How these axons select a specific pathway is not known. Here, we used a microarray-based approach to identify genes expressed in R8 neurons as they extend into the brain. We found that Roundabout-3 (Robo3), an axon-guidance receptor, is expressed specifically and transiently in R8 growth cones. In wild-type animals, posterior-most R8 axons extend along a border of glial cells demarcated by the expression of Slit, the secreted ligand of Robo3. In contrast, robo3 mutant R8 axons extend across this border and fasciculate inappropriately with other axon tracts. We demonstrate that either Robo1 or Robo2 rescues the robo3 mutant phenotype when each is knocked into the endogenous robo3 locus separately, indicating that R8 does not require a function unique to the Robo3 paralog. However, persistent expression of Robo3 in R8 disrupts the layer-specific targeting of R8 growth cones. Thus, the transient cell-specific expression of Robo3 plays a crucial role in establishing neural circuits in the Drosophila visual system by selectively regulating pathway choice for posterior-most R8 growth cones.
DOI	10.1073/pnas.1103419108
Related Publication(s)
Personal communication to FlyBase	P{sens-GAL4.B}1. Schulze, 2012.12.6, P{sens-GAL4.B}1. [FBrf0220211]
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Secondary IDs
Language of Publication	English
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Parent Publication
Publication Type	Journal
Abbreviation	Proc. Natl. Acad. Sci. U.S.A.
Title	Proceedings of the National Academy of Sciences of the United States of America
Publication Year	1915-
ISBN/ISSN	0027-8424
Data from Reference
Aberrations (1)
	Df(2L)Exel7006
Alleles (18)
	Avic\GFP^{S65T.Ubi-p63E.T:SV40\nls2} Ecol\lacZ^Rh5.-560 lea^{robo3.HR.T:Ivir\HA1} Mmus\Cd8a^{Scer\UAS.T:Avic\GFP} robo3¹ robo3³ robo3^{robo3.HR.T:Ivir\HA1} robo3^{Scer\UAS.T:Ivir\HA1,T:SS-wg} robo3^unspecified robo^{robo3.HR.T:Ivir\HA1} run^{G163R.Scer\UAS} run^Scer\UAS.cKa Scer\GAL4^C3 Scer\GAL4^repo Scer\GAL4^robo3-NP4968 Scer\GAL4^sens.PB sens^unspecified sli^k04807b
Constructs (9)
	P{C3-GAL4} P{GawB} P{Rh5-lacZ.-560} P{sens-GAL4.B} P{UAS-mCD8::GFP.L} P{UAS-robo3.HA1} P{UAS-run.G163R} P{UAS-run.K} P{Ubi-GFP(S65T)nls}
Genes (11)
	Avic\GFP Ecol\lacZ Fas2 lea Mmus\Cd8a robo robo3 run Scer\GAL4 sens sli
Insertions (3)
	P{GAL4}repo P{GawB}NP4968 P{lacW}sli^k04807b
Natural transposons (1)
	P-element