Hox and Fox

摘要

A network of Hox factors specifies the identity of motor neurons in the spinal cord. Studies of an essential Fox-class accessory factor illuminate the developmental and evolutionary subtlety of the process. The vertebrate central nervous system (CNS) contains many classes of neurons that have specialized properties. Imagine the problem of creating this cellular diversity, in which neurons that look alike have in fact acquired fine-grained distinctions to ensure that the proper synaptic connections with other neurons are established and maintained. There are an estimated 100 trillion synapses in the brains of the most complex vertebrates, and neuro-biologists are finding that nature has devised a multitude of clever strategies to guide neuron development and connectivity.