Bagnall K M, Sanders E J, Higgins S J, Leam H
Department of Anatomy and Cell Biology, University of Alberta, Edmonton, Canada.
Anat Embryol (Berl). 1988;178(2):183-90. doi: 10.1007/BF02463652.
We have examined the effects on vertebral development of various combinations of somite removal in two day old chick embryos as shown by vertebral formation after a further seven days of incubation. Each combination produced one of a variety of results ranging from completely normal vertebral formation, through fusion of various vertebral elements, to the absence of complete vertebral halves and the formation of hemivertebrae. Assessment of our operating ability showed that we were removing at least 90% of the somitic material and therefore these results suggest that there is a regulating mechanism available to the embryo, at least with regards to vertebral development. When two consecutive somites were removed, vertebrae frequently developed that were lacking certain elements. This suggests that the somitic cells are already determined with regards to formation of specific vertebral elements. Experiments involving the removal of a bilateral pair of somites (a repetitive unit) also provided evidence of a counting mechanism which ensures that the correct number of total vertebrae are present.
我们研究了在两天大的鸡胚中去除不同组合的体节对脊柱发育的影响，这通过再孵化七天后的椎体形成来体现。每种组合产生了一系列不同的结果，从完全正常的椎体形成，到各种椎骨元素的融合，再到完全缺失椎体的一半并形成半椎体。对我们操作能力的评估表明，我们至少去除了90%的体节物质，因此这些结果表明，胚胎存在一种调节机制，至少在脊柱发育方面是这样。当连续去除两个体节时，经常会发育出缺少某些元素的椎骨。这表明体节细胞在特定椎骨元素的形成方面已经被确定。涉及去除双侧一对体节（一个重复单元）的实验也提供了一种计数机制的证据，该机制确保存在正确数量的总椎骨。
