Similarities Between Archenteron and Blastocoelĥ. Archenteron develops into the digestive tube later. Archenteron is the primary gut located in the gastrula. Blastula folds inwards and enlarges to make gastrula, which is a multilayered structure containing primary germ layers. And, this fluid-filled cavity of blastula is known as blastocoel. It is a hollow sphere of cells surrounding an inner fluid-filled cavity. Morula becomes the blastula at the seventh cleavage. Morula is an early stage of the embryo, which contains 16 cells. The embryo undergoes mitotic divisions and cellular differentiation, making a multicellular embryo. The zygote eventually turns into an embryo. When combined with perturbation experiments to investigate molecular and biomechanical underpinnings of morphogenesis, our technique should help to advance our understanding of the fundamentals of development.Fertilization is the event of sexual reproduction that forms a diploid zygote. A transient ectodermal ridge, formed in association with the confrontation of ventral and head mesendoderm on the blastocoel roof, is identified. Moreover, digitally determined volume balances confirm that early archenteron inflation occurs through the uptake of external water. Differential flow analysis separates collective from relative cell motion to assign propulsion mechanisms. laevis embryos, including vegetal endoderm rotation, archenteron formation, changes in the volumes of cavities within the porous interstitial tissue between archenteron and blastocoel, migration/confrontation of mesendoderm and closure of the blastopore. We demonstrate that this powerful four-dimensional imaging technique provides high-resolution views of gastrulation processes in wild-type X. Here we use non-invasive in vivo, time-lapse X-ray microtomography, based on single-distance phase contrast and combined with motion analysis, to examine the course of embryonic development. None of these methods allows cell behaviours to be observed with micrometre-scale resolution throughout the optically opaque, living embryo over developmental time. In Xenopus laevis, the South African clawed frog and also in zebrafish, cell and tissue movements have been studied in explants.sup.2,3, in fixed embryos.sup.4, in vivo using fluorescence microscopy.sup.5,6 or microscopic magnetic resonance imaging.sup.7.
BLASTOPORE ARCHENTERON BLASTOCOEL SERIES
Important morphogenetic movements occur throughout embryogenesis, but in particular during gastrulation when a series of dramatic, coordinated cell movements drives the reorganization of a simple ball or sheet of cells into a complex multi-layered organism.sup.1. An ambitious goal in biology is to understand the behaviour of cells during development by imaging-in vivo and with subcellular resolution-changes of the embryonic structure. This new '4D' technique should be applicable in the fields of genetics, molecular and developmental biology and medicine. By analysing individual cell trajectories, collective tissue motion and the evolution of morphological features, the authors visualize known gastrulation movements and reveal the formation of a structure not reported on previously. Ralf Hofmann, Jubin Kashef and colleagues have developed a non-invasive in vivo time-lapse phase-contrast X-ray microtomography technique that allows the observation of gastrulation. But the study of gastrulation, the stage at which the embryo has formed three layers arranged around a central cavity, has been hampered by the lack of high-quality live-imaging methods useable on intact Xenopus embryos, which are opaque at early stages. New dimensions in vertebrate embryo microtomography Xenopus laevis - the South African clawed frog - is an important model organism, and much of our understanding of the vertebrate embryology derives from this system. Abstract : Opaque tissues provide a challenge for live imaging of Xenopus laevis development a problem solved by in vivo time-lapse X-ray microtomography that is shown to provide a high-resolution three-dimensional view of structural changes and dynamics of gastrulation, and that is applied to identify and analyse new aspects of gastrulation in frog embryos.
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