The axial skeleton is divided into different regions based on its morphological features. In particular, in birds and mammals, ribs are present only in the thoracic region. The axial skeleton is derived from a series of somites. In the thoracic region of the axial skeleton, descendants of somites coherently penetrate into the somatic mesoderm to form ribs. In regions other than the thoracic, descendants of somites do not penetrate the somatic lateral plate mesoderm. We performed live-cell time-lapse imaging to investigate the difference in the migration of a somite cell after contact with the somatic lateral plate mesoderm obtained from different regions of anterior-posterior axis in vitro on cytophilic narrow paths. We found that a thoracic somite cell continues to migrate after contact with the thoracic somatic lateral plate mesoderm, whereas it ceases migration after contact with the lumbar somatic lateral plate mesoderm. This suggests that cell-cell interaction works as an important guidance cue that regulates migration of somite cells. We surmise that the thoracic somatic lateral plate mesoderm exhibits region-specific competence to allow penetration of somite cells, whereas the lumbosacral somatic lateral plate mesoderm repels somite cells by contact inhibition of locomotion. The differences in the behavior of the somatic lateral plate mesoderm toward somite cells may confirm the distinction between different regions of the axial skeleton.

中文翻译：

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鸡中轴骨骼区域特异性肋骨形成的体外模型：体节和侧板细胞之间的细胞间相互作用

轴向骨骼根据其形态特征分为不同的区域。特别是，在鸟类和哺乳动物中，肋骨仅存在于胸部区域。轴向骨骼来自一系列体节。在轴向骨骼的胸椎区域，体节的后代连贯地渗透到体细胞中胚层中形成肋骨。在胸椎以外的区域，体节的后代不会穿透体细胞侧板中胚层。我们进行了活细胞延时成像，以研究体节细胞与从体外前后轴不同区域在亲细胞狭窄路径上获得的体细胞侧板中胚层接触后迁移的差异。我们发现胸体节细胞在与胸体侧板中胚层接触后继续迁移，而在与腰椎体侧板中胚层接触后停止迁移。这表明细胞间相互作用是调节体节细胞迁移的重要指导线索。我们推测胸椎体侧板中胚层表现出区域特异性能力以允许体节细胞穿透，而腰骶体侧板中胚层通过运动的接触抑制来排斥体节细胞。体细胞侧板中胚层对体节细胞行为的差异可能证实了轴向骨骼不同区域之间的区别。我们推测胸椎体侧板中胚层表现出区域特异性能力以允许体节细胞穿透，而腰骶体侧板中胚层通过运动的接触抑制来排斥体节细胞。体细胞侧板中胚层对体节细胞行为的差异可能证实了轴向骨骼不同区域之间的区别。我们推测胸椎体侧板中胚层表现出区域特异性能力以允许体节细胞穿透，而腰骶体侧板中胚层通过运动的接触抑制来排斥体节细胞。体细胞侧板中胚层对体节细胞行为的差异可能证实了轴向骨骼不同区域之间的区别。