Originally published as Genetics Published Articles Ahead of Print on September 9, 2008.

Genetics, Vol. 180, 885-893, October 2008, Copyright © 2008
doi:10.1534/genetics.108.092908

Bursicon Signaling Mutations Separate the Epithelial–Mesenchymal Transition From Programmed Cell Death During Drosophila melanogaster Wing Maturation

Jeanette E. Natzle1, John A. Kiger, Jr. and M. M. Green

Section of Molecular and Cellular Biology, University of California, Davis, California 95616

1 Corresponding author: Section of Molecular and Cellular Biology, University of California, 1 Shields Ave., Davis, CA 95616.
E-mail: jenatzle{at}ucdavis.edu

Following eclosion from the pupal case, wings of the immature adult fly unfold and expand to present a flat wing blade. During expansion the epithelia, which earlier produced the wing cuticle, delaminate from the cuticle, and the epithelial cells undergo an epithelial–mesenchymal transition (EMT). The resulting fibroblast-like cells then initiate a programmed cell death, produce an extracellular matrix that bonds dorsal and ventral wing cuticles, and exit the wing. Mutants that block wing expansion cause persistence of intact epithelia within the unexpanded wing. However, the normal progression of chromatin condensation and fragmentation accompanying programmed cell death in these cells proceeds with an approximately normal time course. These observations establish that the Bursicon/Rickets signaling pathway is necessary for both wing expansion and initiation of the EMT that leads to removal of the epithelial cells from the wing. They demonstrate that a different signal can be used to activate programmed cell death and show that two distinct genetic programs are in progress in these cells during wing maturation.


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Genetics 2008 180: NP. [Full Text]