Retinal axon target selection in Drosophila is regulated by a receptor protein tyrosine phosphatase.
Different Drosophila photoreceptors (R cells) connect to neurons in different optic lobe layers. R1-R6 axons project to the lamina; R7 and R8 axons project to separate layers of the medulla. We show a receptor tyrosine phosphatase, PTP69D, is required for lamina target specificity. In Ptp69D mutants, R1-R6 project through the lamina, terminating in the medulla. Genetic mosaics, transgene rescue, and immunolocalization indicate PTP69D functions in R1-R6 growth cones. PTP69D overexpression in R7 and R8 does not respecify their connections, suggesting PTP69D acts in combination with other factors to determine target specificity. Structure-function analysis indicates the extracellular fibronectin type III domains and intracellular phosphatase activity are required for targeting. We propose PTP69D promotes R1-R6 targeting in response to extracellular signals by dephosphorylating substrate(s) in R1-R6 growth cones.
Garrity
P A
PA
Howard Hughes Medical Institute, Department of Biological Chemistry, Molecular Biology Institute, University of California School of Medicine, Los Angeles 90095, USA.
Lee
C H
CH
Salecker
I
I
Robertson
H C
HC
Desai
C J
CJ
Zinn
K
K
Zipursky
S L
SL
D000818:Animals; D001369:Axons / Q000502:physiology; D004330:Drosophila / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D020439:Growth Cones / Q000502:physiology; D006868:Hydrolysis; D009154:Mutation; D009411:Nerve Endings / Q000502:physiology; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000502:physiology; D012160:Retina / Q000502:physiology / Q000648:ultrastructure
D017027:Protein Tyrosine Phosphatases