<p>Supplementary Figure 1 Cell death seems to be unaffected in aurA mutant brains. Both wild-type (A) and aurA17961 mutant brains (A’) display similar numbers of Caspase-3- expressing cells. DNA is in blue.</p><p>Supplementary Figure 2 aurA display overgrowth phenotype in MACRM clones. Single</p><p>NB MARCM clones were marked by CD8 (A’, B’, C’, D’, E’, F’). In aurA8839 clones, multiple cells expresses Mira (B), Wor (D), and CycE (F) compared to wild-type clones in which only one cell (NB) expresses Mira (A), Wor (C), and CycE (E).</p><p>Supplementary Figure 3 Numb is a tumor suppressor in larval brains. Single NB</p><p>MARCM clones were marked by CD8 in A’, B’, C’, D’. In numb15 clones, most of cells expresses Mira (B) but very few cells expresses Pros (D) in nucleus compared to wild-type clones in which a single NB expresses Mira (A), and most of cells express nuclear Pros (C). </p><p>Supplementary Figure 4 Notch is necessary and sufficient for NB proliferation. A-D’, overexpression of Nact in the clone induces NB overproliferation. Clones were marked by -</p><p>Gal in A’, B’, C’, D’. In Nact clones, most of cells express Dpn (B) and Elav is almost absent</p><p>(D) compared to control clones in which a single NB expresses Dpn (A) and most of cells express Elav (C). E-G’, Overexpression of Nact results in upregulation of CycE and dMyc.</p><p>Overexpression of Nact by a wor-Gal4 driver controlled by a tubulin-Gal80ts in the whole larval brain results in NB overproliferation when shifted to 29C after larval hatching (E’).</p><p>Mutants have supernumerary number of NBs marked by Dpn (E’) and upregulation of CycE</p><p>(F’) and dMyc (G’) compared to a control wor-Gal4;tubulin-Gal80ts brain that expresses Dpn</p><p>(E), CycE (F), and dMyc (G) normally. H, H’, the number of CycE-expressing cells in</p><p>Notchts-1 larval central brains (H’) is decreased compared to wild-type (H).</p><p>1</p>