Kablar B, Rudnicki M A
Institute for Molecular Biology and Biotechnology, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada.
Dev Biol. 1999 Apr 1;208(1):93-109. doi: 10.1006/dbio.1998.9184.
Mice lacking the transcription factors Myf-5 and MyoD lack all skeletal muscle and therefore present a unique opportunity to investigate the dependence of nervous system development on myogenesis. Motor neurons arose normally in the spinal cord of mutant embryos and by birth all somatic motor neurons were eliminated by apoptosis. By contrast, interneurons were not affected. Proprioceptive sensory neurons in the dorsal root ganglia underwent apoptosis. The facial motor nucleus was ablated of motor neurons and contained large numbers of apoptotic bodies. Surprisingly, giant pyramidal neurons were absent in the motor cortex without any corresponding evidence of apoptosis. The epaxial and cutaneous component of dorsal ramus failed to form in the absence of the myotome. Therefore, we conclude that nervous development is more intimately coupled to skeletal myogenesis than has previously been understood.
缺乏转录因子Myf-5和MyoD的小鼠没有所有骨骼肌，因此提供了一个独特的机会来研究神经系统发育对肌生成的依赖性。运动神经元在突变胚胎的脊髓中正常产生，到出生时，所有躯体运动神经元都通过凋亡被消除。相比之下，中间神经元未受影响。背根神经节中的本体感觉感觉神经元发生凋亡。面神经运动核中的运动神经元被消除，并且含有大量凋亡小体。令人惊讶的是，运动皮层中没有巨型锥体神经元，且没有任何相应的凋亡证据。在没有肌节的情况下，背支的轴上和皮肤成分未能形成。因此，我们得出结论，神经发育与骨骼肌生成的耦合比以前所理解的更为密切。
