AP-2α AND AP-2β REGULATE DORSAL INTERNEURON SPECIFICATION IN THE SPINAL CORD

To date, five AP-2 genes that encode AP-2 alpha, beta, gamma, delta and epsilon have been identified in vertebrates and they have been reported to be key regulators of embryonic development. However, the role of AP-2 family members in the development of central nervous system (CNS) has not been characterized. In the present study, we systematically examined the spatiotemporal expression pattern of AP-2 genes in the developing spinal cord of mouse and chick embryos and found that AP-2 alpha and AP-2 beta are specifically expressed in post-mitotic dorsal interneurons. Loss-of-function analysis using in ovo electroporation in embryonic chick spinal cord preliminarily demonstrated that cAP-2 alpha and cAP-2 beta regulates dorsal Class A and Class B interneuron specification, respectively. Gain-of-function experiments further revealed that misexpression of cAP-2 alpha, but not cAP-2 beta, was able to induce the ectopic generation of Class A interneurons. Together, our studies indicated that AP-2 family members, AP-2 alpha and AP-2 beta, have distinct functions in the regulation of dorsal interneuron development. (C) 2016 IBRO. Published by Elsevier Ltd. All rights reserved.