FIG. 6.

SpEts4 activates the SpHE promoter via the Ets element. (A) The effect of the Ets element on SpHE promoter activity in vivo was determined in the context of the intact −310 promoter (upper two constructs) and with a mutated version from which sequences between bp −90 and −240 had been deleted (lower two constructs). CAT reporter activity expressed from microinjected constructs from 75 embryos was assayed at the blastula stage. (B) CAT activity elicited by addition of the SpHE −250 Ets site (open box) to the SpHE basal promoter region (line) (bp −90 to +20). (C) Transactivation of the SpHE Ets site transgene by coinjection of SpEts4 mRNA. Levels of construct DNA were determined by slot blotting (left), using aliquots of the same embryo batches as assayed for CAT activity.