| |
Fig. 1. tbx2 expression in the blastula and gastrula stage ectoderm is
dependent on Xema/Foxi1e activity. A: Xema morpholino-mediated
knockdown (Xema MO) inhibits expression of tbx2. RT-PCR analysis of
early gastrula stage explants. Ornithine decarboxylase (ODC) was used
as a loading control (Bassez et al., 1990). B: Whole-mount in situ
hybridization of early gastrula stage embryos (stage 10.5). Tbx2 expression
is seen as a blue stain throughout the animal pole of albino
embryos; tbx2 expression is excluded from the vegetal pole. Expression
of the panmesodermal marker Xbra is only detected in the marginal
zone of gastrula stage embryos, as expected (Smith et al., 1991).
C: RT-PCR analysis of tbx2 in late blastula stage explants. tbx2 is
expressed in the animal cap and excluded from vegetal pole explants;
vegt is only expressed in vegetal explants, as expected (Lustig et al.,
1996; Stennard et al., 1996; Zhang and King, 1996; Horb and Thomsen,
1997). D: Inner and outer layers of early gastrula stage ectoderm
were separated and analyzed by RT-PCR for expression of tbx2. tbx2
is expressed in the inner layer of the ectoderm; delta is only expressed
in the inner layer, and epidermal keratin is only expressed in the outer
layer (Jonas et al., 1985; Chalmers et al., 2002). All experiments shown
or described in this figure, and throughout the manuscript, were performed
at least three times. |
