Graded expression of Zfp462 in the embryonic mouse cerebral cortex

We describe the isolation and embryonic pattern of expression of mouse Zfp462, a novel zinc finger protein gene. Zfp462 was isolated in a microarray-based search to identify genes differentially expressed in the late embryonic mouse cerebral cortex. The mouse Zfp462 deduced amino acid sequence is 2500 residues in length and contains 23 C(2)H(2)-type zinc finger motifs. Zfp462 shares low homology (30%) with non-vertebrate zinc finger proteins, suggesting that it is vertebrate-specific. However, domains found only in vertebrate-specific zinc finger proteins, such as the KRAB and SCAN domains, were not identified in Zfp462. We show that Zfp462 is expressed in the developing central nervous system, branchial arches, otic vesicles, sensory ganglia, somites and limbs. In the central nervous system, Zfp462 is expressed at the headfold stage and is later expressed in the developing forebrain, brainstem and spinal cord. Interestingly, beginning at E13.5, Zfp462 is expressed in a graded pattern in the mouse cerebral cortex. As predicted by the microarray analysis, Zfp462 is expressed at its highest levels in the caudal and medial cerebral cortex. Its expression in cortical layers is greatest in the marginal zone, the cortical plate and the subventricular zone. Zfp462 thus belongs to a growing family of molecular determinants that are expressed in a graded pattern in the developing cerebral cortex. This family includes transcription factor-encoding genes such as COUP-TF1, Emx2 and Pax6, which have been implicated in the process of cortical arealization.