Natural variation in embryo mechanics: gastrulation in Xenopus laevis is highly robust to variation in tissue stiffness
Article first published online: 18 DEC 2008
Copyright © 2008 Wiley-Liss, Inc.
Volume 238, Issue 1, pages 2–18, January 2009
How to Cite
von Dassow, M. and Davidson, L. A. (2009), Natural variation in embryo mechanics: gastrulation in Xenopus laevis is highly robust to variation in tissue stiffness. Dev. Dyn., 238: 2–18. doi: 10.1002/dvdy.21809
- Issue published online: 18 DEC 2008
- Article first published online: 18 DEC 2008
- Manuscript Accepted: 8 OCT 2008
- National Institutes of Health. Grant Number: R01-HD044750
Additional Supporting Information may be found in the online version of this article.
|DVDY21809SuppFig1.pdf||17K||Figure S1 [sm001.pdf]: Diagram of channel opening with partially aspirated tissue. (A) The basic geometry: ‘rc’: channel radius; ‘L1’: initial aspirated length at initial pressure ‘P1’; ‘L2’: final aspirated length at pressure ‘P2’; ‘D’: displacement following suction with a pressure difference ‘P’. (B) Approximations for estimating error in measured displacement. We approximate the tissue shape at time i as a circular arc, ‘Ai’, centered at ci with radius ri. Lengths D, Li and rc are defined in figure S1; ‘α’, viewing angle; ‘Dap’, apparent displacement; ‘o’, center of channel opening; ‘bi’, the point of tangency between curve Ai (with i = 1 or 2) and line of sight at viewing angle α; ‘V’, vector from point b1 to b2. (C) The expected ratio of the apparent displacement, Dap, to the actual displacement, D, for values of L1 and L2 (in μm) representing the range of values for L1 and L2 in our experiments (rc = 62.5 μm).|
|DVDY21809SuppFig2.pdf||11K||Figure S2 [sm002.pdf]: Effect of (A) concentration of dissolved salts, (B) pH, and (C) 0.3 μM Latrunculin B on Ln-transformed stiffness measured at 450 s following suction. Data were separated by clutch. Sample sizes in parentheses, error bars show ± 1 SD.|
|dvdy_21809_sm_SuppMoviesS1.mov||4674K||Movie S1 [sm003.mov]: Micro-aspiration with only very small, localized contraction-relaxation events. This embryo was at stage 9 at the start, and stage 10 at the end of the movie. The site of aspiration was on the ventral marginal zone. The movie shows 5 minutes of no suction followed by 45 minutes at -5.4 Pa suction (starting at time 0). The green line in figure 2A illustrates this embryo.|
|dvdy_21809_sm_SuppMoviesS2.mov||5184K||Movie S2 [sm004.mov]: A series of contractions followed by slight relaxation during micro-aspiration. This embryo was at stage 9 at the start, and stage 10 at the end of the movie. The site of aspiration was on the lateral side of the embryo. The movie shows 15 minutes with no suction followed by 45 minutes of suction at -5.4 Pa (starting at time 0). The black line in main text figure 2A illustrates this embryo. The jitters prior to suction were from adjustments to the focus.|
|dvdy_21809_sm_SuppMoviesS3.mov||5787K||Movie S3 [sm005.mov]: A contraction followed by relaxation during micro-aspiration. Note that the contraction initiates at discrete location on tissue surface. This embryo was at stage 9 at the start, and stage 10 at the end of the movie. The site of aspiration was on the ventral-lateral marginal zone. The movie shows 15 minutes with no suction followed by 45 minutes of suction at -5.4 Pa (starting at time 0). The embryo is illustrated by the gold line in main text figure 2A, and is illustrated in main text figure 2C. There is some leakage around the embryo for a period following the start of contraction. Jitters prior to suction were from changes in focus.|
|dvdy_21809_sm_SuppMoviesS4.mov||5393K||Movie S4 [sm006.mov]: A relaxation during micro-aspiration. This embryo was at stage stage 10. The site of aspiration was on the vegetal endoderm. The movie shows 15 minutes with no suction followed by 45 minutes of suction at -5.4 Pa (starting at time 0). The blue line in main text figure 2A illustrates the embryo. The jitters prior to suction were from changes in focus.|
|dvdy_21809_sm_SuppMoviesS5.mov||3127K||Movie S5 [sm007.mov]: Contraction events, and deformations due to cell division visible on the dorsal side of the animal cap in an embryo at stage 10.5 to 11. The video shows one large and two small contractions (circled in black) and several cell divisions (two of which are circled in white) in which the deformation of the neighboring cells is evident. The embryo rolls slowly in the video because it was only barely constrained.|
|dvdy_21809_sm_SuppMoviesS6.mov||2540K||Movie S6 [sm008.mov]: A rapid, large-scale contraction of tissue on the dorsal side of a stage 12.5 embryo is visible at the very beginning of the movie. This embryo is illustrated in main text figure 2E. The embryo was gently constrained to hold it in place, but otherwise it was not manipulated.|
|dvdy_21809_sm_SuppMoviesS7.mov||3401K||Movie S7 [sm009.mov]: Rapid contraction at the blastopore in a gently constrained embryo: stage 10, dorsal side of embryo.|
|dvdy_21809_sm_SuppTables.doc||148K||Supplemental Tables. [sm010.doc]|
|DVDY21809SuppModelsl.doc||79K||Supplementary Models. [sm011.doc]|
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