Centro Andaluz de Biología del Desarrollo, (CSIC)-Universidad Pablo de Olavide, Sevilla, Spain.
PLoS One. 2011;6(9):e23893. doi: 10.1371/journal.pone.0023893. Epub 2011 Sep 16.
During embryonic development, there are numerous cases where organ or tissue formation depends upon the migration of primordial cells. In the Drosophila embryo, the visceral mesoderm (vm) acts as a substrate for the migration of several cell populations of epithelial origin, including the endoderm, the trachea and the salivary glands. These migratory processes require both integrins and laminins. The current model is that αPS1βPS (PS1) and/or αPS3βPS (PS3) integrins are required in migrating cells, whereas αPS2βPS (PS2) integrin is required in the vm, where it performs an as yet unidentified function. Here, we show that PS1 integrins are also required for the migration over the vm of cells of mesodermal origin, the caudal visceral mesoderm (CVM). These results support a model in which PS1 might have evolved to acquire the migratory function of integrins, irrespective of the origin of the tissue. This integrin function is highly specific and its specificity resides mainly in the extracellular domain. In addition, we have identified the Laminin α1,2 trimer, as the key extracellular matrix (ECM) component regulating CVM migration. Furthermore, we show that, as it is the case in vertebrates, integrins, and specifically PS2, contributes to CVM movement by participating in the correct assembly of the ECM that serves as tracks for migration.
在胚胎发育过程中，有许多器官或组织的形成依赖于原始细胞的迁移。在果蝇胚胎中，内脏中胚层（vm）是几种上皮来源的细胞群体迁移的基质，包括内胚层、气管和唾液腺。这些迁移过程既需要整合素又需要层粘连蛋白。目前的模型是，迁移细胞中需要αPS1βPS（PS1）和/或αPS3βPS（PS3）整合素，而 vm 中需要αPS2βPS（PS2）整合素，它执行一个尚未确定的功能。在这里，我们表明 PS1 整合素对于中胚层来源的细胞——尾内脏中胚层（CVM）在 vm 上的迁移也是必需的。这些结果支持了这样一种模型，即 PS1 可能已经进化到获得整合素的迁移功能，而与组织的起源无关。这种整合素功能具有高度特异性，其特异性主要存在于细胞外结构域。此外，我们已经确定了层粘连蛋白α1,2 三聚体作为调节 CVM 迁移的关键细胞外基质（ECM）成分。此外，我们还表明，正如在脊椎动物中一样，整合素，特别是 PS2，通过参与作为迁移轨迹的 ECM 的正确组装，有助于 CVM 运动。
