Interestingly F-actin was consistently oriented toward the blastopore lip in dorsal and lateral cells, but oriented parallel to the lip in ventral regions. Definition: 'The opening of the archenteron to the exterior, marking the point of origin of the archenteron and the caudal end of the embryo. The F-actin network is organized differently in each region with the highest percentage of alignment occurring in the lateral region. The sequence can be divided into several steps: (1) As the dorsal lip of the blastopore forms, leading edge mesoderm (shown in orange here) is rotated up into. In contrast, cells lateral and ventral to the blastopore are less polarized and have tortuous cell boundaries. Cells dorsal to the blastopore, which are fated to become neural plate ectoderm, are polarized and have straight boundaries. But with time the marginal zone involutes to form the mesodermal mantle and. Strain rate mapping of the dorsal, ventral and lateral epithelial cells proximal to the blastopore reveals changing patterns of strain rate throughout closure. zone, which was defined as the region that is marginal to and above the blastopore. During this time course, the embryo also stiffens 1.5 fold. blastopore, organizer, spemann, mangold, xenopus, frog, twinned. We find that the embryo generates a ramping magnitude of force until it reaches a peak force on the order of 0.5 μN. of the dorsal lip of the blastopore from a donor to a host of a closely related. We describe the mechanics of blastopore closure at multiple scales and in different regions around the blastopore by characterizing large scale tissue deformations, cell level shape change and subcellular F-actin organization and by measuring tissue force production and structural stiffness of the blastopore during gastrulation. These forces are tuned to generate sustained blastopore closure throughout the course of gastrulation. Blastopore closure in the amphibian embryo involves large scale tissue reorganization driven by physical forces. The dorsal blastopore lip is a source of signals inducing planar cell polarity in the Xenopus neural plate Biol Open.

Xenopus blastopore