PNG-1, A NERVOUS SYSTEM-SPECIFIC ZINC-FINGER GENE, IDENTIFIES REGIONSCONTAINING POSTMITOTIC NEURONS DURING MAMMALIAN EMBRYONIC-DEVELOPMENT

To identify genes associated with early postmitotic cortical neurons, gene fragments were examined for expression in postmitotic, but not pr oliferative, zones of the embryonic murine cortex. Through this approa ch, a novel member of the zinc finger gene family, containing 6 rs, wa s isolated and named postmitotic neural gene-1, or png-1. Embryonic pn g-1 expression was: 1) nervous system-specific; 2) restricted to zones containing postmitotic neurons; and 3) detected in all developing neu ral structures examined. In the cortex, png-1 expression was first obs erved on embryonic day 11, correlating temporally and spatially with t he known generation of the first cortical neurons. Gradients of png-1 expression throughout the embryonic central nervous system further cor related temporally and spatially with known gradients of neuron produc tion. With development, expression remained restricted to postmitotic zones, including those containing newly-postmitotic neurons. Png-1 was also detected within two days of neural retinoic acid induction in P1 9 cells, and expression increased with further neuronal differentiatio n. These data implicate png-1 as one of the earliest molecular markers for postmitotic neuronal regions and suggest a function as a panneura l transcription factor associated with neuronal differentiation. (C) 1 997 Wiley-Liss, Inc.