Figure 14

NSCs during advanced neurogenesis of Stylopallene cheilorhynchus and Nymphon gracile . Optical sections of FM 1-43FX-labeled specimens of Stylopallene cheilorhynchus (A–C) and tubulin-labelled specimens of Nymphon gracile (D,E) with nuclear counterstain. Oblique slicers have been aligned to show asymmetry/symmetry of forming sister cells as clearly as possible. Therefore, sections are frequently oriented obliquely horizontal. Dashed vertical lines mark the VMR. Asterisks label large NSCs that are not in division. White spots indicate epidermal cells. (A–C) Walking leg ganglion 1 of PS 1. (A) Apical section through morphologically left hemi-ganglion anlage. Note significant size differences between NSCs and all other cells. Arrow points at NSC in metaphase, note off-centre position of the metaphase plate. (B) Slightly basal to A. Two asymmetrical NSCs divisions are marked. Arrows mark the larger, arrowheads the smaller of the newly forming sister cells. (C) Section through morphologically right hemi-ganglion anlage. Arrow points at NSC in prophase. Open arrowheads point at forming sister cells of a symmetrical division of an INP amongst the more peripheral GCs. (D,E) Walking leg ganglion 1 of PS 2. (D) Apical section through morphologically right hemi-ganglion anlage. Arrows indicate three NSCs in metaphase (~tangential orientation). Open arrowhead marks smaller symmetrical division (telophase) of an epidermal precursor bordering the hemi-ganglion anlage. (E) Apical section through morphologically left hemi-ganglion anlage. Two asymmetrical NSC divisions are marked. Arrows mark the larger, arrowheads the smaller of the newly forming sister cells. Bluish halo on the right side represents autofluorescence of the larval cuticle.