Lanser M E, Fallon J F
J Neurosci. 1984 Aug;4(8):2043-50. doi: 10.1523/JNEUROSCI.04-08-02043.1984.
This is a report on the development of the lateral motor column (LMC) in the limbless mutant chick embryo. The limbless mutant was used to study the effects of the absence of a periphery on the developing nervous system. The limbless mutant provides a unique opportunity to compare the effects on the LMC of deletion of a limb caused by the genotype with those seen following surgical removal of the limb primordium. Cell counts of the total number of motoneurons in the LMC at both the brachial and lumbar levels were done in a large series of limbless embryos and on their normal siblings. In normal embryos, a substantial loss of LMC motoneurons was observed during the course of normal development. At the brachial level, 54% of the initial LMC cell population was lost between day 6 and day 18. At the lumbar level, 40% of the initial population was lost between the 6th and 12th days of development with no further loss through day 18. An even more massive cell loss was observed in the limbless mutant LMC at both brachial and lumbar spinal cord levels between day 5 and day 12. This resulted in the elimination of at least 85% of the motoneurons that were initially present in the limbless LMC. Our data demonstrate that the effects of peripheral deprivation on LMC development in the limbless mutant are similar to those seen following surgical removal of the periphery. The initial production of motoneurons and assembly of the LMC did not appear to be significantly affected by the mutation, while the subsequent degeneration of LMC motoneurons is greatly accelerated and increased in comparison to the normal.
这是一篇关于无肢突变鸡胚中侧运动柱（LMC）发育的报告。无肢突变体被用于研究外周缺失对发育中的神经系统的影响。无肢突变体提供了一个独特的机会，可将基因型导致的肢体缺失对LMC的影响与手术切除肢体原基后观察到的影响进行比较。对大量无肢胚胎及其正常同胞进行了臂部和腰部水平LMC中运动神经元总数的细胞计数。在正常胚胎中，在正常发育过程中观察到LMC运动神经元大量减少。在臂部水平，最初LMC细胞群的54%在第6天至第18天之间丢失。在腰部水平，最初细胞群的40%在发育的第6天至第12天之间丢失，到第18天没有进一步减少。在无肢突变体的LMC中，在第5天至第12天期间，在臂部和腰部脊髓水平均观察到更大量的细胞丢失。这导致至少85%最初存在于无肢LMC中的运动神经元被消除。我们的数据表明，外周剥夺对无肢突变体中LMC发育的影响与手术切除外周后观察到的影响相似。运动神经元的初始产生和LMC的组装似乎没有受到突变的显著影响，而与正常情况相比，LMC运动神经元随后的退化大大加速且增加。
