Molecular Immunology, National Institute of Medical Research, London NW7 1AA, United Kingdom.
Proc Natl Acad Sci U S A. 2010 Jul 27;107(30):13414-9. doi: 10.1073/pnas.1003747107. Epub 2010 Jul 8.
Thymus organogenesis requires coordinated interactions of multiple cell types, including neural crest (NC) cells, to orchestrate the formation, separation, and subsequent migration of the developing thymus from the third pharyngeal pouch to the thoracic cavity. The molecular mechanisms driving these processes are unclear; however, NC-derived mesenchyme has been shown to play an important role. Here, we show that, in the absence of ephrin-B2 expression on thymic NC-derived mesenchyme, the thymus remains in the cervical area instead of migrating into the thoracic cavity. Analysis of individual NC-derived thymic mesenchymal cells shows that, in the absence of ephrin-B2, their motility is impaired as a result of defective EphB receptor signaling. This implies a NC-derived cell-specific role of EphB-ephrin-B2 interactions in the collective migration of the thymic rudiment during organogenesis.
胸腺器官发生需要多种细胞类型的协调相互作用，包括神经嵴 (NC) 细胞，以协调发育中的胸腺从第三咽囊到胸腔的形成、分离和随后的迁移。驱动这些过程的分子机制尚不清楚；然而，已经表明 NC 衍生的间充质在其中发挥了重要作用。在这里，我们表明，在胸腺 NC 衍生的间充质上缺乏 Ephrin-B2 表达的情况下，胸腺仍然位于颈部区域，而不是迁移到胸腔中。对单个 NC 衍生的胸腺间充质细胞的分析表明，在缺乏 Ephrin-B2 的情况下，由于 EphB 受体信号的缺陷，它们的迁移能力受损。这意味着 EphB-ephrin-B2 相互作用在器官发生过程中胸腺原基的集体迁移中具有 NC 衍生的细胞特异性作用。
