Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
Department of Prehospital Emergency Medical Sciences, Faculty of Health Sciences, Hiroshima International University, 555-36 Kurosegakuendai, Higashihiroshima City, Hiroshima, 739-2695, Japan.
Anat Sci Int. 2022 Sep;97(4):380-390. doi: 10.1007/s12565-022-00652-z. Epub 2022 Feb 20.
The thoracic ventral body wall consists of the rib, the sternum, the intercostal muscles, and the connective tissues surrounding them. The ribs and the intercostal muscles are derived from the somite. The connective tissues are derived from the somatic layer of the lateral plate mesoderm, somatopleure. The lateral growth of the somatopleure forms the primary ventral body wall. The migration of somitic cells into the somatopleure generates the secondary body wall. As the migrating behavior of the somatopleural cells during secondary body wall formation is still unclear, we investigate here the migratory behavior of the somatopleural cells in the thorax during chicken ventral body wall development by labeling the thoracic somatopleural cells one-somite-wide by DiI labeling or gene transfection of the enhanced green fluorescent protein and observe their distribution assisted by the tissue-clearing technique FRUIT. Our labeling experiments revealed the rostral migration of the somatopleural cells into a deep part of the thoracic body wall in embryonic day 6.5 chickens. For embryonic day 8.5 chickens, these deep-migrating somatopleural cells were found around the sternal ribs. Thus, we identified the double-layered two-directional migrating pathways of the somatopleural cells: the rostral migration of the deep somatopleural cells and the lateral migration of the superficial somatopleural cells. Our findings imply that the rostral migration of deep somatopleural cells and the lateral migration of superficial ones might be associated with the developing sternal ribs and the innervation of the thoracic cutaneous nerves, respectively.
胸腹壁的前腹壁由肋骨、胸骨、肋间肌和周围的结缔组织组成。肋骨和肋间肌来源于体节，结缔组织来源于侧板中胚层的体壁层，体壁层。体壁层的侧向生长形成初级前腹壁。体节细胞迁移到体壁层中产生次级体壁。由于次级体壁形成过程中体壁层细胞的迁移行为尚不清楚，我们通过 DiI 标记或增强型绿色荧光蛋白的基因转染对一个体节宽的胸壁体壁层细胞进行标记，并用组织清除技术 FRUIT 观察它们的分布，从而研究鸡前腹壁发育过程中胸壁体壁层中体壁层细胞的迁移行为。我们的标记实验揭示了胚胎第 6.5 天鸡的体壁层细胞向胸壁深部的向前迁移。对于胚胎第 8.5 天的鸡，这些深迁移的体壁层细胞被发现位于胸骨肋骨周围。因此，我们确定了体壁层细胞的双层双向迁移途径：深体壁层细胞的向前迁移和浅体壁层细胞的侧向迁移。我们的发现表明，深体壁层细胞的向前迁移和浅体壁层细胞的侧向迁移可能分别与胸骨肋骨的发育和胸皮神经的神经支配有关。
