Drosophila sensory neurons require Dscam for dendritic self-avoidance and proper dendritic field organization.
A neuron's dendrites typically do not cross one another. This intrinsic self-avoidance mechanism ensures unambiguous processing of sensory or synaptic inputs. Moreover, some neurons respect the territory of others of the same type, a phenomenon known as tiling. Different types of neurons, however, often have overlapping dendritic fields. We found that Down's syndrome Cell Adhesion Molecule (Dscam) is required for dendritic self-avoidance of all four classes of Drosophila dendritic arborization (da) neurons. However, neighboring mutant class IV da neurons still exhibited tiling, suggesting that self-avoidance and tiling differ in their recognition and repulsion mechanisms. Introducing 1 of the 38,016 Dscam isoforms to da neurons in Dscam mutants was sufficient to significantly restore self-avoidance. Remarkably, expression of a common Dscam isoform in da neurons of different classes prevented their dendrites from sharing the same territory, suggesting that coexistence of dendritic fields of different neuronal classes requires divergent expression of Dscam isoforms.
Soba
Peter
P
Howard Hughes Medical Institute, Department of Physiology, University of California, San Francisco, Rock Hall, 1550 4th Street, San Francisco, CA 94143, USA.
Zhu
Sijun
S
Emoto
Kazuo
K
Younger
Susan
S
Yang
Shun-Jen
SJ
Yu
Hung-Hsiang
HH
Lee
Tzumin
T
Jan
Lily Yeh
LY
Jan
Yuh-Nung
YN
D000818:Animals; D030801:Animals, Genetically Modified; D015815:Cell Adhesion Molecules; D048430:Cell Shape / Q000502:physiology; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D004330:Drosophila; D029721:Drosophila Proteins / Q000502:physiology*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D009154:Mutation / Q000502:physiology; D009475:Neurons, Afferent / Q000145:classification / Q000166:cytology / Q000502:physiology*; D012679:Sense Organs / Q000166:cytology; D013194:Staining and Labeling
D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; C491736:Dscam1 protein, Drosophila