Fig. 5.

Of'hb stains the posterior growth zone (double arrowheads) and the neuroectoderm and newly formed neuroblasts (mn mandibular segment, mx maxillary segment, la labial segment, T1–T3 first to third thoracic segments, A1 first abdominal segment). a Of'hb in a normal germ band stage embryo. The posterior extent of neural Of'hb expression is indicated by an arrow. b In the Of'br-depleted germ band, the posterior extent of neural Of'hb expression lags behind growth zone expression by several additional segments. In addition, Of'hb expression shows that the two tracks of neural tissue are joined in T2 (arrow)