Molecular cloning and characterization of the mouse E2F6 gene

E2F6 is the most recently identified member of the E2F family. In this stud y, the murine E2F6 gene was cloned and found to consist of eight exons. Ana lysis of its 5 ' flanking region revealed two transcription start sites. Th e proximal promoter region contained no TATA or CAAT box. We also identifie d a novel E2F6 mRNA containing the alternative exon 2. The E2F6 mRNAs are h ighly expressed during mouse embryogenesis and are present in all adult tis sues examined. Moreover, E2F6 shows a unique expression pattern in synchron ized mouse embryonic fibroblasts. E2F6 expression rapidly increases during the G0-G1 transition, reaching its higher level in mid-GI, and remains rela tively constant thereafter. These findings suggest that E2F6 may contribute to the regulation of events throughout the cell cycle. Isolation of the mu rine E2F6 gene is a step toward generation of genetically modified mouse mo dels that will help to understand the functions of E2F6. (C) 2001 Academic Press.