The dorsal involuting marginal zone stiffens anisotropically during its convergent extension in the gastrula of Xenopus laevis

摘要: Physically, the course of morphogenesis is determined by distribution and timing force production in embryo mechanical properties tissues on which these forces act. We have miniaturized a standard materials-testing procedure (the stress-relaxation test) to measure viscoelastic dorsal involuting marginal zone, prechordal mesoderm, vegetal endoderm Xenopus laevis embryos during gastrulation. focused because it undergoes convergent extension (an important wide-spread morphogenetic process) drives involution, blastopore closure elongation embryonic axis. show that zone stiffens gastrulation, stiffening special property this region rather than general whole embryo, greater along anteroposterior axis mediolateral changes cytoskeleton or extracellular matrix are necessary for stiffening, although cell-cell adhesions cell-matrix not ruled out. These findings provide baseline data future experiments can be designed make specific, testable predictions about roles cytoskeleton, intercellular adhesion extension, as well role early development.