...Andy J. Chang; Donald Morisato Dorsoventral polarity of the Drosophila embryo requires maternal spätzle-Toll signaling to establish a nuclear gradient of Dorsal protein. The shape of this gradient is altered in embryos produced by females carrying dominant alleles of easter (ea D) . The easter...

.... The last protease in this sequence is encoded by easter , which is a candidate to activate proteolytically the ligand encoded by spätzle . Here, we demonstrate biochemically that the zymogen form of Easter is processed in vivo by a proteolytic cleavage event that requires the three upstream proteases...

...Rebecca Chasan; Yishi Jin; Kathryn V. Anderson The product of the Drosophila easter gene, a member of the trypsin family of serine proteases, must be more active ventrally than dorsally to promote normal embryonic polarity. The majority of the easter protein in the embryo is present...