Final answer:
Inhibitors of microtubule formation can block cortical rotation in early embryos, resulting in defects in the establishment of the body axis.
Step-by-step explanation:
Inhibitors of microtubule formation, such as vinblastine and colchicine, can block cortical rotation in early embryos. Cortical rotation is a process in which the outer layer of cells in an embryo rotates relative to the inner layer of cells, establishing the body axis. Microtubules play a crucial role in this process by mediating the movement of cytoplasmic components. When inhibitors of microtubule formation are present, this movement is disrupted, leading to defects in the establishment of the body axis.