Figure 2

Morphogenesis of the head region of P. tepidariorum. Schematic drawings of embryonic heads in ventral view at stage 10 (A), stage 11 (B), stage 12 (C), stage 13 (D), and stage 14 (E). Stages were defined after [57]. The non-neurogenic ectoderm is shown in gray; the neurogenic ectoderm is shown in orange. The non-neurogenic ectoderm at the anterior rim of the head lobes (dark gray) gradually overgrows the neurogenic ectoderm. The anterior (AF) and lateral furrow (LF) in the brain primordium are indicated. In the non-neurogenic head ectoderm, the primordia of the eyes are also indicated: ALE, anterior lateral eyes; PLE, posterior lateral eyes; MLE, median lateral eyes; ME, median eyes.