Nuclear factor one transcription factors in CNS development.

Transcription factors are key regulators of central nervous system (CNS) development and brain function. Research in this area has now uncovered a new key player-the nuclear factor one (NFI) gene family. It has been almost a decade since the phenotype of the null mouse mutant for the nuclear factor one A transcription factor was reported. Nfia null mice display a striking brain phenotype including agenesis of the corpus callosum and malformation of midline glial populations needed to guide axons of the corpus callosum across the midline of the developing brain. Besides NFIA, there are three other NFI family members in vertebrates: NFIB, NFIC, and NFIX. Since generation of the Nfia knockout (KO) mice, KO mice for all other family members have been generated, and defects in one or more organ systems have been identified for all four NFI family members (collectively referred to as NFI here). Like the Nfia KO mice, the Nfib and Nfix KO mice also display a brain phenotype, with the Nfib KO forebrain phenotype being remarkably similar to that of Nfia. Over the past few years, studies have highlighted NFI as a key payer in a variety of CNS processes including axonal outgrowth and guidance and glial and neuronal cell differentiation. Here, we discuss the importance and role of NFI in these processes in the context of several CNS systems including the neocortex, hippocampus, cerebellum, and spinal cord at both cellular and molecular levels.