Fig. 4. Sequences outside the Xbra T box restrict induction by VegT and Eomesodermin. (A) The parent Xbra, VegT and Eomesodermin proteins, and chimeric versions thereof. XVX consists of the VegT T box surrounded by Xbra non-T box sequences; XEX contains the Eomesodermin T box surrounded by Xbra non-T box sequences; and VXV consists of the Xbra T box surrounded by VegT non-T box sequences. (B) Activation of Goosecoid, Pintallavis and Chordin by XVX and XEX is lower than activation of the same genes by the parent proteins, suggesting that the non-T box sequences of Xbra reduce levels of induction. (C) Goosecoid, Pintallavis and Chordin are not induced by a protein comprising the Xbra T box surrounded by VegT non-T box sequences.
