MIXL -induced expression of αT4-globin inXenopus animal caps.

Synthetic mRNAs (300 pg or 1 ng RNAs) were injected into Xenopus one-cell embryos in 2 separate sets. At the 8-cell stage, animal caps were excised and the explants were cultured in the presence of human recombinant bFGF (hbFGF). At the equivalent of stage 36, the animal caps from each set was pooled separately for RNA extraction and RT-PCR analysis. Twenty-seven cycles of multiplex PCR with the primer pairs for αT4-globin and EF1-α genes were performed. Note the αT4-globin expression in wild-type (WT) MIXL-injected animal caps but not in animal caps injected with homeobox-less MIXL(ΔMIXL) or FGF-treated embryos. +, 300 pg mRNA; ++, 1 ng mRNA.