Mechanochemical regulation of oscillatory follicle cell dynamics in the developing Drosophila egg chamber.
Bottom Line: We propose that follicle cells in the epithelial layer contract against pressure in the expanding egg chamber.The activation process is cooperative, leading to a limit cycle in the myosin dynamics.The model demonstrates that in principle, mechanochemical interactions are sufficient to drive patterning and morphogenesis, independent of patterned gene expression.
Affiliation: Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218.Show MeSH
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Mentions: In the egg chamber, the basal lamina is a highly cross-linked and complex structure, with collagens comprising ∼50% of the protein (Kalluri, 2003). Follicle cells adhere to the basal lamina via integrin-mediated adhesions that contain focal adhesion proteins such as talin and paxillin (Figure 5A and Supplemental Figure S8). We examined the effect of the basal lamina on follicle cell oscillations by treating wild-type cells with collagenase to partially remove the basal lamina surrounding the egg chamber (Figure 5B). Figure 5C shows the distribution of oscillation periods for control and collagenase-treated samples. On collagenase treatment, some cells no longer exhibit oscillations. Other cells show an increased oscillation period. The mean period in the control condition is 5.6 min, which increases to 10.6 min. In addition, the egg chamber radius decreases by ∼20% upon collagenase treatment (Figure 5C, inset).
Affiliation: Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218.