Journal
JOURNAL OF CELL SCIENCE
Volume 119, Issue 6, Pages 1118-1129Publisher
COMPANY BIOLOGISTS LTD
DOI: 10.1242/jcs.02832
Keywords
cadherin superfamily; Flamingo; dendrite; Drosophila
Categories
Ask authors/readers for more resources
Seven-pass transmembrane cadherins (7-TM cadherins) play pleiotropic roles in epithelial planar cell polarity, shaping dendritic arbors and in axonal outgrowth. In contrast to their role in planar polarity, how 7-TM cadherins control dendritic and axonal outgrowth at the molecular level is largely unknown. Therefore, we performed extensive structure-function analysis of the Drosophila 7-TM cadherin Flamingo (Fmi) and investigated the activities of individual mutant forms mostly in dendritogenesis of dendritic arborization (da) neurons. One of the fmi-mutant phenotypes was overgrowth of branches in the early stage of dendrite development. In da neurons but not in their adjacent non-neuronal cells, expression of a truncated form (Delta N) that lacks the entire cadherin repeat sequence, rescues flies-at least partially - from this phenotype. Another phenotype is observed at a later stage, when dendritic terminals outgrowing from the contralateral sides meet and then avoid each other. In the fmi mutant, by contrast, those branches overlapped. Overexpression of the Delta N form on the wild-type background phenocopied the overlap phenotype in the mutant, and analysis in heterologous systems supported the possibility that this effect might be because the Fmi-Fmi homophilic interaction is inhibited by Delta N. We propose that a dual molecular function of Fmi play pivotal roles in dendrite morphogenesis. In the initial growing phase, Fmi might function as a receptor for a so-far-unidentified ligand and this hypothetical heterophilic interaction would be responsible for limiting branch elongation. At a later stage, homophilic Fmi-binding at dendro-dendritic interfaces would elicit avoidance between dendritic terminals.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available