The CAG Promoter is More Active than the CEF Promoter for the Expression of Transgenes in a Mouse ES Cell Line E14-Derived EB3 Cells

Abstract

ABSTRACTMouse embryonic stem (ES) cells are useful for characterizing the functions of specific genes in pluripotency and differentiation, especially through genetic modifications. The activity of promoters for transgene expression was considered to vary in different transfected ES cell lines, and basic scientific knowledge regarding promoter activities in mouse ES cell lines will be very valuable. In this report, we compared the activities of viral and housekeeping gene promoters in a mouse ES E14-derived EB3 cells and somatic cells both in transient and stable expression systems. An immediate early promoter of human cytomegalovirus was potently inactivated in a stable expression system in EB3 cells, and it was active in EB3 cells in a transient expression system and in somatic cells both in transient and stable expression systems. In contrast, the CAG and CEF promoters, which are chicken β-actin gene- and human polypeptide elongation factor-1α gene-based promoters, respectively, were capable of efficient expression of transgenes not only in a transient expression system, but also in a stable expression system even in EB3 cells. However, it was noteworthy that the CAG promoter was more active than the CEF promoter. To the best of our knowledge, this is the first delineation of promoter activities in E14-derived mouse ES cells both in transient and stable expression systems.