EXPRESSION OF THE E2F-1 DP-1 TRANSCRIPTION FACTOR IN MURINE DEVELOPMENT/

Because of its critical role in the control of cell proliferation and differentiation, we postulated that E2F-1 could have a role in murine development, To this end, the organ and developmental expression of th e E2F-1 transcription factor was analyzed from midgestation to late-st age embryogenesis. We demonstrate that the mRNA levels for E2F-1 and i ts heterodimeric partner DP-1 reach maximal levels in the late embryon ic and early postnatal period but decline in the later postnatal and a dult periods, Additionally, using high resolution in situ hybridizatio n, high expression of E2F-1 was observed in specific cells of individu al tissues, suggesting that the role of E2F-1 may be more complex than previously indicated from cell culture studies. Furthermore, the unus ual pattern of E2F-1 and DP-1 developmental expression may have an ess ential role in certain cells and tissues in the late embryonic and ear ly postnatal period.