Denaxa Myrto, Kyriakopoulou Katerina, Theodorakis Kostas, Trichas George, Vidaki Marina, Takeda Yasuo, Watanabe Kazutada, Karagogeos Domna
University of Crete Medical School, Heraklion 71110, Crete, Greece.
Dev Biol. 2005 Dec 1;288(1):87-99. doi: 10.1016/j.ydbio.2005.09.021. Epub 2005 Oct 12.
The neural cell adhesion molecule TAG-1 has been implicated in the tangential migration of neurons of the caudal medulla and of cortical interneurons. In the former case, protein is expressed by the neurons as they migrate, and blocking its function results in altered and reduced migration in vitro. In the latter case, protein is expressed, in part, by the pathway the interneurons use to reach the cortex, and in vitro experiments propose a role for TAG-1 in this system, as well. However, the in vivo requirement of TAG-1 in these migrations has not been investigated. In this report, we analyze the developmental phenotype of TAG-1-deficient animals in these two migratory systems. We show that mutant mice have smaller lateral reticular nuclei as a result of increased cell death in the superficial migratory stream of the caudal medulla. On the other hand, the absence of TAG-1 does not affect the number, morphology, timing and routes of GABAergic interneurons that migrate from the ganglionic eminences to the cortex. Therefore, TAG-1 function is required for the survival of the neurons of some precerebellar nuclei, while it is not required for cortical interneuron migration in vivo.
神经细胞黏附分子TAG-1与延髓尾部神经元和皮质中间神经元的切向迁移有关。在前一种情况下，神经元迁移时会表达该蛋白，阻断其功能会导致体外迁移发生改变并减少。在后一种情况下，该蛋白部分由中间神经元到达皮质所使用的路径表达，体外实验也表明TAG-1在这个系统中起作用。然而，尚未研究TAG-1在这些迁移中的体内需求。在本报告中，我们分析了TAG-1缺陷动物在这两个迁移系统中的发育表型。我们发现，由于延髓尾部浅层迁移流中细胞死亡增加，突变小鼠的外侧网状核较小。另一方面，TAG-1的缺失不影响从神经节隆起迁移到皮质的GABA能中间神经元的数量、形态、时间和路径。因此，TAG-1功能是某些小脑前核神经元存活所必需的，而在体内皮质中间神经元迁移中则不需要。
