mother cell of mesoderm

例句：

1. 1. The development of theembryo is divided into three main stages:primitive streak, mesoderm, and endoderm.
   胚胎发育分为三个主要阶段：原始脊索、中胚层和内胚层。
2. 2.During the formation of the neural tube,the mesoderm cells begin todifferentiate into different types of neurons.
   在形成神经管的过程中，中胚层细胞开始分化成不同类型的神经元。
3. 3. Themesoderm layeris responsible for forming the body's primary muscle tissue.
   中胚层层负责形成身体的主要肌肉组织。