Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics.
Lumbar lateral motor columns and hindlimbs of two Xenopus laevis chromosome mosaics.
复制标题
两个非洲爪蟾染色体嵌合体的腰椎侧向运动柱和后肢。
DOI：
10.1002/aja.1001910406
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Sperry,DG
中科院分区：
文献类型：
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作者：
Sperry,DG
两条染色体嵌合体非洲爪蟾，一个蝌蚪和一个变态动物，在它们的大脑和脊髓的左右两侧都有不同大小的神经元，它们有相同长度的左右腰椎外侧运动柱（L - lmc），但由显著不同数量的运动神经元组成（由较大细胞组成的一侧运动神经元少40%）。在变态动物中，腰椎的一部分是两侧对称的；两侧的细胞较小，每切片运动神经元的数量相同。这些嵌合表明，柱长度和运动神经元密度（每切片的数量）是或可以被双边调节的，并且改变细胞大小会影响控制细胞密度的因素，但不会影响柱长度。除了周围神经外，没有证据表明后肢组织有任何两侧差异。66期嵌合体中L - LMC运动神经元数量的两侧差异是否与后肢的任何特征相对应尚不清楚，但在早期和晚期嵌合体动物中类似的侧对侧差异支持了这样一种观点，即产生初始数量的东西也可能决定最终运动神经元的数量。
Two chromosome mosaicXenopus laevis, one tadpole and one metamorphic animal, both with different sizes of neurons on the left and right sides of their brains and spinal cords, have left and right lumbar lateral motor columns (L‐LMCs) of equal lengths but composed of strikingly different numbers of motoneurons (40% fewer motoneurons on the side composed of larger cells). One portion of the lumbar cord in the metamorphic animal is bilaterally symmetrical; the cells on both sides are small and the numbers of motoneurons per section are the same. The mosaics demonstrate that column length and motoneuron density (number per section) are, or can be, regulated bilaterally and that changing cell size affects factors controlling cell density but not column length. Except for the peripheral nerves, there is no evidence of any side‐to‐side differences in the hindlimb tissues. Whether the side‐to‐side difference in L‐LMC motoneuron number in the stage 66 mosaic corresponds to any feature of the hindlimbs is unknown, but similar side‐to‐side differences in an early and a late stage mosaic animal support the idea that whatever creates the initial number may also determine the final number of motoneurons.