Round and round gets you somewhere: collective cell migration and planar polarity in elongating Drosophila egg chambers

Abstract

Planar polarity is a developmental mechanism wherein individual cell behaviors are coordinated across a two-dimensional plane. A great deal of attention has been paid to the roles that the Frizzled/Strabismus and Fat/Dachsous signaling pathways play in this process; however, it is becoming increasingly clear that planar polarity can also be generated through alternate mechanisms. This review focuses on an unconventional form of planar polarity found within the follicular epithelium of the Drosophila egg chamber that helps to create the elongated shape of the egg. We highlight recent studies showing that the planar polarity in this system arises through collective migration of the follicle cells and the resulting rotational motion of the egg chamber.

Symmetry Breaking in an Edgeless Epithelium by Fat2-Regulated Microtubule Polarity

“…A mechanism for amplification in the follicle involves whole-tissue rotation. Preventing rotation by disrupting actin or integrins causes a rapid loss of all PCP organization primed in the germarium (Bilder and Haigo, 2012; Cetera and Horne-Badovinac, 2015). Interestingly, just as MTs are largely dispensable for PCP after actin PCP becomes established (Figs.…”

“…The Drosophila egg chamber (also called the follicle) is an acinar tissue that exhibits a non-canonical form of PCP (reviewed in (Bilder and Haigo, 2012; Cetera and Horne-Badovinac, 2015). This PCP is seen within the ‘follicle epithelium’ that encases the germline.…”

A hormonal cue promotes timely follicle cell migration by modulating transcription profiles

“…1A). Multiple follicle cell migrations and cell rearrangements must occur sequentially for normal oogenesis (Berg, 2005; Cetera and Horne-Badovinac, 2015; Wu et al, 2008). In mid-oogenesis, six to eight border cells arise within the follicular epithelium that surrounds the germ line.…”

Drosophila Oogenesis: An Elegant Model System in Cell and Developmental Biology

“…Oogenesis in Drosophila melanogaster is a complex developmental process which involves extensive cellular remodeling and communication [1][2][3]. The entire process of oogenesis occurs within Drosophila ovary which harbors 16 to 20 long tube-like structures known as ovarioles.…”