Control of mouse U1 snRNA gene expression during in vitro differentiation of mouse embryonic stem cells.

摘要

Previous studies have shown that early in mouse development, 2 classes of U1 small nuclear RNAs, mU1a and mU1b, are synthesised. As development proceeds, transcription of the embryo-specific mU1b genes is selectively down-regulated to a barely detectable level. In this study, it was found that during in vitro differentiation of mouse embryonic stem (ES) cells, both exogenously introduced and endogenous U1b genes were subject to normal developmental regulation. Thus, ES cells represent a convenientisogenic system for studying the control of expression of developmentally regulated snRNA genes. Using this system, a region in the proximal 5' flanking region, located outside the proximal sequence element, was identified that was responsible for differential transcription of the mU1a and mU1b genes in both developing cells and transiently transfected NIH 3T3 cells.