Fig. 4

chch mutants show altered expression levels of early mesodermal and endodermal markers. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis of transcript levels in chch mutants at 6 hours postfertilization (hpf) (gastrulation) and 9 hpf (90% epiboly). Relative comparisons were made between chch^sbu50/sbu50 mutant and wild-type (WT, defined as 1) embryos. A: During blastula stage, chch mutants exhibit increased ntl, mixer, and gsc transcript levels as well as decreased sip1a expression. Levels of chd, flh, and sip1b were not significantly different between the two groups at this stage. B: chch^sbu50/sbu50 embryos at 90% epiboly show increased expression of ntl and mixer while exhibiting a decrease in chd compared with wild-type. However expression of flh and gsc were unchanged. Error bars indicate standard error of the mean. Single, double, and triple asterisks indicate statistical significance (P < 0.05, P < 0.001, and P < 0.0001 respectively).