Figure 4.

Various Stat spacer lengths modify in vivo transcriptional activation. (A) Levels of expression of the SLF4 enhancer containing the normal 4n4n D. melanogaster Stat-binding sites. (B) Enhanced expression of an SLF4 enhancer in which the conserved fourth Stat 4n site is transformed to 3n. (C) An SLF4 enhancer in which the third site has been transformed to 2n and there is a 3n site transformation on the fourth site. Note that the levels of expression in (C) are lower than those in (B), and more similar to those of (A). Stat, signal transducer and activator of transcription.