Identification of CXorf1, a novel intronless gene in Xq27.3, expressed in human hippocampus

We have identified and characterized a novel human gene (Nomenclature Commi ttee of the Genome Database GDB-assigned symbol CXorf1) that maps to the lo ng arm of the X chromosome in Xq27 between loci DXS369 and DXS181, approxim ately 2.5 Mb centromeric to the FMR1 gene. The CXorf1 gene is conserved in primates, cow, and horse but not in mouse and rat. Northern blot analysis r evealed two transcripts, present in the brain and in the G361. melanoma cel l line. En situ hybridization experiments performed on sections of human hi ppocampus showed a clear, uneven localization of the CXorf1 mRNA in specifi c subfields of this brain area. In particular, CXorf1 was localized in the granular-cell layer of the dentate gyrus and in the CA2-CA3 subfields of Am mon's horn. CXorf1 is one of the first genes from this region to be charact erized in detail and, on the basis of its chromosomal location and expressi on pattern, may have an important function in the brain.