Massarwa R'ada, Ray Heather J, Niswander Lee
Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel.
Wiley Interdiscip Rev Dev Biol. 2014 Jan-Feb;3(1):59-68. doi: 10.1002/wdev.120. Epub 2013 May 29.
The neural tube (NT), the embryonic precursor of the vertebrate brain and spinal cord, is generated by a complex and highly dynamic morphological process. In mammals, the initially flat neural plate bends and lifts bilaterally to generate the neural folds followed by fusion of the folds at the midline during the process of neural tube closure (NTC). Failures in any step of this process can lead to neural tube defects (NTDs), a common class of birth defects that occur in approximately 1 in 1000 live births. These severe birth abnormalities include spina bifida, a failure of closure at the spinal level; craniorachischisis, a failure of NTC along the entire body axis; and exencephaly, a failure of the cranial neural folds to close which leads to degeneration of the exposed brain tissue termed anencephaly. The mouse embryo presents excellent opportunities to explore the genetic basis of NTC in mammals; however, its in utero development has also presented great challenges in generating a deeper understanding of how gene function regulates the cell and tissue behaviors that drive this highly dynamic process. Recent technological advances are now allowing researchers to address these questions through visualization of NTC dynamics in the mouse embryo in real time, thus offering new insights into the morphogenesis of mammalian NTC.
神经管（NT）是脊椎动物脑和脊髓的胚胎前体，由一个复杂且高度动态的形态学过程产生。在哺乳动物中，最初平坦的神经板会双侧弯曲并抬起，形成神经褶，随后在神经管闭合（NTC）过程中，这些褶在中线处融合。该过程中任何一个步骤出现故障都可能导致神经管缺陷（NTDs），这是一类常见的出生缺陷，大约每1000例活产中就有1例发生。这些严重的出生异常包括脊柱裂，即脊柱水平闭合失败；颅脊柱裂，即沿整个身体轴的神经管闭合失败；以及无脑畸形，即颅神经褶未能闭合，导致暴露的脑组织退化，称为无脑儿。小鼠胚胎为探索哺乳动物神经管闭合的遗传基础提供了绝佳机会；然而，其子宫内发育也给更深入理解基因功能如何调节驱动这一高度动态过程的细胞和组织行为带来了巨大挑战。最近的技术进步使研究人员能够通过实时观察小鼠胚胎中的神经管闭合动态来解决这些问题，从而为哺乳动物神经管闭合的形态发生提供新的见解。
