X-ray phase-contrast in vivo microtomography probes new aspects of Xenopus gastrulation.
X-ray phase-contrast in vivo microtomography probes new aspects of Xenopus gastrulation.
复制标题
作者：
生物学的一个雄心勃勃的目标是通过对胚胎结构的变化进行体内亚细胞分辨率成像来了解细胞在发育过程中的行为。重要的形态发生运动发生在整个胚胎发生过程中，但特别是在原肠胚形成期间，一系列戏剧性的协调细胞运动驱动简单的细胞球或细胞片重组成复杂的多层生物体。在非洲爪蟾，南非爪蛙，也在斑马鱼，细胞和组织的运动已经研究了外植体，在固定的胚胎，在体内使用荧光显微镜或显微磁共振成像。这些方法都不允许在整个光学不透明的活胚胎发育过程中以微米级分辨率观察细胞行为。在这里，我们使用非侵入性的体内，延时X射线显微断层扫描，基于单距离相位对比，结合运动分析，检查胚胎发育的过程。我们证明，这种强大的四维成像技术提供了野生型X原肠形成过程的高分辨率视图。胚胎发育过程中的主要变化包括植物性内胚层的旋转、原肠的形成、原肠与囊胚腔之间多孔间质组织中空腔体积的变化、中内胚层的迁移/对峙和囊胚孔的闭合。差分流分析分离集体从相对细胞运动分配推进机制。此外，数字确定的体积平衡证实，早期archenteron膨胀发生通过吸收外部水。一个短暂的外胚层脊，形成与腹侧和头部中内胚层的囊胚腔屋顶的对抗，被确定。当结合扰动实验来研究形态发生的分子和生物力学基础时，我们的技术应该有助于促进我们对发育基本原理的理解。
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. 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. In Xenopus laevis, the South African clawed frog and also in zebrafish, cell and tissue movements have been studied in explants, in fixed embryos, in vivo using fluorescence microscopy or microscopic magnetic resonance imaging. None of these methods allows cell behaviours to be observed with micrometre-scale resolution throughout the optically opaque, living embryo over developmental time. 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. We demonstrate that this powerful four-dimensional imaging technique provides high-resolution views of gastrulation processes in wild-type X. 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. Differential flow analysis separates collective from relative cell motion to assign propulsion mechanisms. Moreover, digitally determined volume balances confirm that early archenteron inflation occurs through the uptake of external water. A transient ectodermal ridge, formed in association with the confrontation of ventral and head mesendoderm on the blastocoel roof, is identified. 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.
登录
查看更多内容
影响因子：
4.6
作者：
Ewald, AJ;Peyrot, SM;Wallingford, JB
通讯作者：
Wallingford, JB
影响因子：
3.4
作者：
Cloetens, P;Ludwig, W;Peix, G
通讯作者：
Peix, G
影响因子：
--
作者：
KELLER, RE
通讯作者：
KELLER, RE
影响因子：
56.9
作者：
Dubertret, B;Skourides, P;Libchaber, A
通讯作者：
Libchaber, A
影响因子：
1.6
作者：
Snigirev, A;Snigireva, I;Schelokov, I
通讯作者：
Schelokov, I