Figure 3.

Contributions of odd and runt to the odd-numbered parasegment boundaries. Wild-type embryos or those null mutant for slp (B, D, F), runt (G, I), or double mutant for runt and slp (H, J) were stained (blue) by in situ hybridization to RNA for either odd (left column) or wg (right column), followed by anti-En staining (brown). Note, in slp mutants at stages 7 and 8 (B, D), the expanded odd expression just anterior to odd-numbered En stripes (the posterior parts of PSs 2, 4, 6, and 8 are marked in A–D and F with small squares). At these stages, En expression is approximately normal; however, at stage 9 (F), odd-numbered En stripes have expanded anteriorly, and wg expression in the same regions has been lost. Note also that the regions where neither odd nor En is expressed in runt mutants (G, I) express En in runt, slp double mutants (H, J); PSs 8 and 10, where slp (Fig. 2) and wg (I) are expressed between En stripes in runt single mutants, are marked with red and green bars, respectively.