Fig. 6. Regulation of BMP-dependent mesodermal induction by endofin in Xenopus embryos. Capped RNAs encoding endofin (wild type and mutants) and BMP4 were synthesized in vitro and injected alone or in combination into both animal poles of two-cell-stage embryos. The ectodermal explants (animal caps) from injected embryos were dissected at blastula stages (stage 8.5-9) and cultured until gastrula stages (stage 11) before total RNA was extracted. RT-PCR was performed using the primers for different mesodermal marker genes. EF1- serves as a loading control. Although mutations in the FYVE and SBD domains reduced expression of BMP-responsive genes, the mutation in the PBD domain enhanced BMP-induced marker gene expression.