Netrin-guided accessory cell morphogenesis dictates the dendrite orientation and migration of a Drosophila sensory neuron.
Accessory cells, which include glia and other cell types that develop in close association with neurons, have been shown to play key roles in regulating neuron development. However, the underlying molecular and cellular mechanisms remain poorly understood. A particularly intimate association between accessory cells and neurons is found in insect chordotonal organs. We have found that the cap cell, one of two accessory cells of v'ch1, a chordotonal organ in the Drosophila embryo, strongly influences the development of its associated neuron. As it projects a long dorsally directed cellular extension, the cap cell reorients the dendrite of the v'ch1 neuron and tows its cell body dorsally. Cap cell morphogenesis is regulated by Netrin-A, which is produced by epidermal cells at the destination of the cap cell process. In Netrin-A mutant embryos, the cap cell forms an aberrant, ventrally directed process. As the cap cell maintains a close physical connection with the tip of the dendrite, the latter is dragged into an abnormal position and orientation, and the neuron fails to undergo its normal dorsal migration. Misexpression of Netrin-A in oenocytes, secretory cells that lie ventral to the cap cell, leads to aberrant cap cell morphogenesis, suggesting that Netrin-A acts as an instructive cue to direct the growth of the cap cell process. The netrin receptor Frazzled is required for normal cap cell morphogenesis, and mutant rescue experiments indicate that it acts in a cell-autonomous fashion.
Department of Anatomy and Cell Biology, University of Melbourne, VIC 3010, Australia.
Eli M
EM
Mrkusich
Zalina B
ZB
Osman
Karen E
KE
Bates
Julia M
JM
Marchingo
Molly
M
Duman-Scheel
Paul M
PM
Whitington
D000818:Animals; D002465:Cell Movement; D003712:Dendrites / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000378:metabolism*; D000075386:Netrin Receptors; D000075388:Netrin-1; D000075385:Netrins; D011956:Receptors, Cell Surface / Q000378:metabolism; D011984:Sensory Receptor Cells / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D029721:Drosophila Proteins; D009414:Nerve Growth Factors; C000617352:NetA protein, Drosophila; D000075386:Netrin Receptors; D000075385:Netrins; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; C000617310:fra protein, Drosophila; D000075388:Netrin-1