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Science 336 (6082): 724-727

Copyright © 2012 by the American Association for the Advancement of Science

Mechanical Control of Morphogenesis by Fat/Dachsous/Four-Jointed Planar Cell Polarity Pathway

Floris Bosveld1,*, Isabelle Bonnet1,*, Boris Guirao1,*, Sham Tlili1,{dagger}, Zhimin Wang1, Ambre Petitalot1, Raphaël Marchand1, Pierre-Luc Bardet1, Philippe Marcq2, François Graner1, and Yohanns Bellaïche1,{ddagger}

1 Polarity, Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 Rue d’Ulm, 75248 Paris Cedex 05, France.
2 Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR 168, Université Pierre et Marie Curie, 26 Rue d’Ulm, 75248 Paris Cedex 05, France.


Figure 1
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  		Fig. 1. The Drosophila dorsal thorax as a system for morphogenesis. In all figures, yellow circles, macrochaetae; cyan dashed line, midline. (A) Dorsal thorax tissue labeled with E-Cad:GFP. Yellow region, scutellum; dashed black line, scutum. The black box cut by the midline defines the two "hemi-scutella". (B to D) Maps of proliferation (B), apex area (C), and anisotropy (D), defined as 1 minus the ratio of minor and major axes of the fitting ellipse. White cells are sensory organ precursor cells. (E) Velocity field averaged between 19 and 21 hAPF, represented as arrows. Gray regions are scutum and scutellum flows. (F) Deformation rates averaged between 19 and 21 hAPF, represented as ellipses. Red, elongation; Blue, contraction. Anterior (A). Posterior (P). Scale bars, 100 μm, 9 x 10–2 μm/min [(E), blue arrow], 2.4 x 10–3 min–1 [(F), blue bar].

 

Figure 2
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  		Fig. 2. Ds and Fj expression gradients locally polarize Dachs and Ds. Panels show right-side hemi-scutellum. (A) Quantification of the average gradients of Ds and fj-lacZ (n = 7 hemi-scutella). (B) Mean deformation rates (n = 5 hemi-scutella) between 17:20 and 21:20 hAPF. Deformation rates represented as ellipses. Red, elongation; Blue, contraction. (C and D) Dachs:GFP (D:GFP) and Ds localization. Arrowheads: D:GFP (C) and Ds (D) polarity lines. Yellow ellipses indicate average macrochaete positions ± SD. Scale bars, 10 μm, 10–3 min–1 [(B), blue bar].

 

Figure 3
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  		Fig. 3. Ds and Dachs colocalize and Dachs polarization is associated with tension anisotropy. (A and B) Cells located in a region of the Fj gradient expressing D:GFP and lacking D:GFP (D:GFP–) (A), or overexpressing ds (dsUP cells marked by mRFP, not shown) (B) accumulate D:GFP and Ds at junctions facing the higher Fj concentration (green arrowheads), whereas they are absent at junctions facing the lower Fj concentration (red arrowheads). Yellow arrows: direction of polarization. Yellow dots: dsUP cells abutting the wild-type (WT) cells (B). (C to C") D:GFP [(C) and (C’’)] and Ds [(C’) and (C’’)] colocalize (arrowheads). (D) Anti-Flag blot of GFP-immunoprecipates from cells expressing Flag:Dsintra and GFP; Flag:Dsintra; Flag:Dsintra and D:GFP; Molecular weight (MW) markers in kilodaltons. Although a nonspecific GFP binding was observed, a larger amount of Flag:Dsintra was reproducibly coprecipitated with D:GFP. (E) Plot of the mean speed of vertex relaxation after ablation of junctions with high or low D:GFP. Scale bars: 10 μm.

 

Figure 4
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  		Fig. 4. Dachs polarity lines promote local contractions mainly via cell rearrangements. Averaged maps between 17:20 and 21:20 hAPF. (A and B) Localization of D:GFP (A) and map of D:GFP magnitude and anisotropy (B) quantified by Fourier Transform (FT, n = 3 hemi-scutella). (C to F’) Maps of subtractions of dachsRNAi (n = 5 hemi-scutella) from WT (n = 11 hemi-scutella) and of dsRNAi (n = 5 hemi-scutella) from WT (n = 11 hemi-scutella) for contraction rates [(C) and (D)] and for cell rearrangements [(E) and (F)]. Bars indicate amplitudes and orientations of the differences of contraction rates or cell rearrangements. Maps of the alignment coefficients between the D:GFP FT pattern and the differences in contraction rates [(C’) and (D’)], or between the differences in contraction rates and cell rearrangements within the D:GFP FT pattern [(E’) and (F’)] for WT and dachsRNAi [(C’) and (E’)] and for WT and dsRNAi [(D’) and (F’)]. Local alignment scores [(C’) and (D’), orange; (E’) and (F’), purple] go from 0 (fully anticorrelated), to 1 (fully correlated), through 0.5 (noncorrelated). Significant data are green (B), blue [(C) and (D)], and red [(E) and (F)] bars; other are gray bars [(B) to (F)]. The average score A is calculated over nongray regions. Scale bars, 10 μm, 5.5 x 10–4 min–1 [(C) and (D), blue bars], 1 μm2 min–1 [(E) and (F), red bars].

 

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