MOTOR INNERVATION OF DORSOVENTRALLY REVERSED WINGS IN CHICK QUAIL CHIMERIC EMBRYOS
MOTOR INNERVATION OF DORSOVENTRALLY REVERSED WINGS IN CHICK QUAIL CHIMERIC EMBRYOS
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DOI：
10.1523/jneurosci.13-06-02463.1993
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发表时间：
1993-06-01
影响因子：
5.3
通讯作者：
HOLLYDAY, M
中科院分区：
文献类型：
--
作者：
FERNS, MJ;HOLLYDAY, M
在肢体神经丛中，运动轴突指定肢体肌肉分歧沿着单独的途径，以支配肌肉来源于背侧或腹侧前肌群众。我们已经研究了轴突的指导线索参与这个初始的，具体的路径选择在神经丛的背腹侧（D/V）肢芽翻转神经支配之前。鸡/鹌鹑嵌合体用于确定组织切片中逆转的近端水平。在运动神经元死亡之前的年龄，通过逆行HRP标记来评估背侧或腹侧神经干的投射的特异性。当移植物水平接近神经丛时，轴突纠正了反转，并且反转的肢体及其大体神经模式正常。如果所有这些条件都不满足，则观察到异常的神经支配模式。在宿主组织内、在宿主-移植物边界处以及在旋转的组织内分析轴突轨迹，以确定沿着路径引导线索可能位于何处。特别注意的情况下，轴突补偿逆转项目在雅阁与他们的索马在横向运动柱的位置。在这些纠正的情况下，正常的D/V排序后，在宿主的脊神经，运动轴突改变其轨迹后，进入旋转移植组织，因为他们接近和穿越丛。由于校正是在旋转的组织内，而不是在其近端，D/V通路线索不太可能是远程目标源信号，而是似乎与神经丛区域中的位置信息密切相关，并且在远端脊神经周围的组织中也更接近。
In the limb plexus, motor axons destined for limb muscles diverge along separate pathways to innervate muscles derived from either the dorsal or ventral premuscle masses. We have examined the axonal guidance cues involved in this initial, specific pathway choice at the plexus by making dorsoventral (D/V) limb bud reversals prior to innervation. Chick/quail chimeras were used to determine the proximodistal level of the reversal in tissue sections. The specificity of the projections to dorsal or ventral nerve trunks was assessed by retrograde HRP labeling at ages prior to motoneuron death. Axons corrected for the reversal when the level of the graft was proximal to the plexus, and when the reversed limb and its gross nerve pattern were normal. If all of these conditions were not satisfied, aberrant innervation patterns were observed. Axonal trajectories were analyzed within the host tissue, at the host-graft border, and within rotated tissue to determine where along the pathway guidance cues might be located. Special attention was given to cases in which axons compensated for the reversal to project in accord with the positions of their soma in the lateral motor column. In these correcting cases, after normal D/V sorting in the spinal nerves of the host, motor axons altered their trajectories upon entering rotated graft tissue as they approached and traversed the plexus. Because corrections were within rotated tissue and not proximal to it, the D/V pathway cues are unlikely to be long-range target-derived signals, but rather appear to be closely associated with positional information in the plexus region and also more proximally in the tissue surrounding the distal spinal nerves.