(A) Sequence of Xenopus GDF11 protein. The following conserved regions are present: putative signal sequence (red), TGFß propeptide domain (blue), TGFß mature domain (green). Cleavage sites for BMP-1/Tolloid protease (GD, purple) and furin protease (RSRR, orange) are also indicated. (B) Temporal expression profile of xGDF11. RT-PCR was performed on whole embryo samples harvested at indicated stages. xGDF11 RT-PCR was performed on both +RT and -RT samples. Ornithine decarboxylase (ODC) was used as a loading control. (C) In situ hybridization for xGDF11 from stages 13-37. In stages 20-37, anterior is to the left, dorsal to the top. bp: blastopore, tb: tailbud, br:brain, ba: branchial arches, nc: neurenteric canal, pw: posterior wall of tailbud, cnh: chordoneural hinge.