The functions of Semaphorins in the neural development

During embryogenesis, axons reach their specific targets correctly to form the complex neural network found in the mature functional nervous system. Several groups of axon guidance molecules such as semaphorins, ephrins, netrins, and its have been reported to repel or attract the growing axons that express their cognate receptors. Semaphorins are secreted or transmembrane proteins, and found in both vertebrates and invertebrates. Semaphorins are initially identified as pulsive axon guidance molecules. However, recent many studies suggest that semaphorin family genes perform a variety of important biological functions besides the axon guidance.