Figure 1—figure supplement 1.

Figure 1—figure supplement 1.

Related to Figure 1 (A′) Left panel: diagrammatic overview of the Drosophila wandering third instar larval stage (wL3) brain highlighting the dorso-anterior-lateral region of the central brain which contains neural stem cells of the type I NB lineage. CB central brain; OL optic lobe; M medulla; VNC ventral nerve chord; DAL dorsal anterior lateral region. Right panel: an ex vivo brain imaged in bright field, the blue arrows indicate measurements taken of brain lobe diameter to assess growth in culture. (A′′) Analysis of the increase in brain lobe size in culture compared to in vivo. The left plot shows ex vivo cultured brain lobe diameter increase for Jupiter::GFP; Histone::RFP L3 brains over 24 h (blue trace, n = 3) under wide-field fluorescence imaging conditions. The single red datapoint shows average lobe diameter (n = 13) for freshly isolated brains from free living larvae at the end of wL3, corresponding to the stage expected for 24 h culture. The right hand plot directly compares brain lobe diameter for 24 h cultured and freshly isolated brains from free living larvae at the end of wL3 (ns, Mann-Whitney test, ex-vivo n = 4; in-vivo n = 25). (A′′′ and A′′′′), bright field images at two time-points during culture and examples of freshly dissected free living larvae at corresponding developmental stages, respectively. Scale bars 50 µm.