Dynamics of the control of body pattern in the development of Xenopus laevis. III. Timing and pattern after u.v. irradiation of the egg and after excision of presumptive head endo-mesoderm.
Dynamics of the control of body pattern in the development of Xenopus laevis. III. Timing and pattern after u.v. irradiation of the egg and after excision of presumptive head endo-mesoderm.
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非洲爪蟾发育过程中身体形态控制的动态。
DOI：
10.1242/dev.88.1.135
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
J. Cooke
中科院分区：
文献类型：
--
作者：
J. Cooke
一系列的非洲爪蟾卵批次已暴露于剂量的u. v.（2537 A）光的植物半球在precleavage阶段，计算导致一系列最小的轴向缺陷综合征的发展中的幼虫。在原肠胚在同步受精，但非辐照批成员的发病时间，每个实验组定期扫描，使小的子样品的胚胎可以被搁置，显示特定的，渐进程度的延迟在发病的原肠胚运动的可见。这样的采样被发现有预选胚胎显示一般渐进程度的模式障碍，在幼虫阶段，这一观察是通过组织学检查的前轴解剖扩展。这种检查也是对一系列幼虫中看起来最不异常的成员进行的，这些幼虫是从第10期原肠胚中切除假定的头部内中胚层（传统上称为“组织者”）而产生的（Cooke，1975）。结果支持的概念，生产的最前面的内-中胚层图案的部分（和他们的诱导能力，在引起大脑模式）只发生在材料的时间，在原肠胚活动的发病，是接近正常的发病时间受精后。无论是早期失败的鸡蛋，以产生一个位置的“位置值”对应于这个极端的模式，或更晚的切除该地区从生理正常的原肠胚，结果在一个系统的模式形成永久截断在其顶端（头和背）。没有证据表明，在定位系统中，任何动态会导致这种细胞状态的调节性恢复（发育的最极端“激活”），以响应其在预切割阶段后的缺失。早期的说法（Cooke，1975）认为这可能发生，这是基于对幼虫的不充分分析，通常具有误导性的外部解剖结构。目前的研究结果进行了讨论，支持早期爪蟾图案系统，已在该系列的前两篇论文中开发的整体观点。
A series of Xenopus egg batches has been exposed to doses of u.v. (2537A) light on the vegetal hemisphere at precleavage stages, calculated to result in a range of minimal axial deficiency syndromes in the developing larvae. At the time of onset of gastrulation in synchronously fertilized but non-irradiated batch members, each experimental group was regularly scanned so that small subsamples of embryos could be set aside as showing particular, progressive degrees of delay in onset of the visible gastrulation movements. Such sampling was found to have preselected embryos showing generally progressive degrees of pattern impairment at larval stages, and this observation was extended by histological examination of the anterior axial anatomy. Such examination was also made of the least abnormal-looking members of a series of larvae resulting from excision of the presumptive head endo-mesoderm, traditionally called 'the organizer', from stage-10 gastrulae (Cooke, 1975). The results support the notion that production of the most anterior endo-mesodermal pattern parts (and of their inductive capacities in giving rise to the brain pattern) occurs only in material whose timing, in the onset of gastrulation activity, is close to the normal onset time after fertilization. Either an early failure of the egg to generate a location with the 'position value' corresponding with this extreme of the pattern, or the much later excision of the region from a physiologically normal gastrula, results in a system of pattern formation permanently truncated at its apical (head and dorsal) end. There is no evidence for any dynamic, in the system ascribing position value, that will cause regulative restoration of this cellular state (the most extreme 'activation' for development) in response to its absence after precleavage stages. An earlier statement (Cooke, 1975) that this could occur was based upon inadequate analysis of larvae with an often misleading external anatomy. The present results are discussed as supporting the overall view of the early Xenopus patterning system that has been developed in the previous two papers of the series.
第一次卵裂前离心的非洲爪蟾卵胚胎轴形成位点的实验控制。
影响因子：
2.7
作者：
Black,SD;Gerhart,JC
通讯作者：
Gerhart,JC