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Figure 1. Sequence and expression of Xenopus tgif1. A: Alignment of human (TGIF1), mouse (Tgif1), Xenopus tropicalis (xtr Tgif1), and Xenopus laevis (xla Tgif1) translated amino acid sequences. Identical residues are in black, similar residues are in grey. Boxes above the sequences mark the locations of a CtBP-binding motif, a nuclear-localization sequence, a Tgif-specific motif and an ERK phosphorylation site. The homeodomain is underlined with a dashed line. Arrowheads mark the sites of HPE mutations. Amino acid (a.a.) numbers are indicated for the X. laevis protein. B: Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of tgif1 and tgif2 expression in animal (An) and vegetal (Vg) oocyte halves, compared with whole oocytes (Oo) and stage 10.5 embryos (10.5). The -RT indicates a stage 10.5 sample processed in the absence of reverse transcriptase. C: Quantitative real-time PCR (QPCR) analysis of tgif1 and tgif2 expression during early development. Samples were normalized to odc and values displayed as a percentage relative to an uninjected oocyte sample (relative expression %). D-I: in situ hybridization of tgif1. D: Stage 10.5 (top row) and stage 13 (bottom row) embryos. Both rows show an animal pole view. In the bottom row, anterior is to the left. E: Stage 18, anterior to the left. F,G: Stage 24 (F) and stage 36 (G). H,I: Sections through stage 30 embryos, hindbrain level section (H), spinal cord level section (I). Anterior is to the left. no, notochord. |
