FIGURE 1. Segmentation (in this case abnormal) in the Drosophila embryo.
From the following article:
Peter Dearden and Michael Akam
Nature 406, 131-132(13 July 2000)
doi:10.1038/35018180
Normally the segment-polarity gene network generates a linear array of 14 segments, each bounded by a stripe of cells expressing the engrailed gene. This 'two-tailed' embryo shows how the segment-polarity network can make regular patterns, even with abnormal inputs. Signals from the mutant mother have triggered two arrays of segments to form back-to-back. Where they meet, a circular segment boundary has formed (here revealed by staining for Engrailed protein).
MICHAEL AKAM
