A negative regulatory element in a prespore-specific promoter of Dictyostelium discoideum

We previously isolated several 'promoter-trap" transformants in which inser tion of a promoterless beta-galactosidase gene into the genome caused expre ssion of beta-galactosidase in specific cell types. The upstream flanking r egion was rescued from one transformant specifically expressing beta-galact osidase in prespore cells. We sequenced the promoter of the gene that is fu sed in-frame with lacZ and characterised a negative element that inhibits e xpression in pstO cells (a subtype of prestalk cells). Gel-retardation assa ys show that a developmentally regulated factor(s) recognises and binds to this element. (C) 1999 Elsevier Science B.V. All rights reserved.