chromosomes. As wild type, w1118 was often used. Unless otherwise stated, flies were obtained from the

Jagla)(De Graeve et al., 2004). ladybird early fragment K driving Gal4 (referred to as lbe(K)-Gal4), generated by inserting the K fragment into the pMB3 Gal4 vector (Certel and Thor, 2004). UAS-nls-myc-EGFP (referred to as UAS-nmEGFP), UAS-myc-EGFP–farnesylation, sqzGal4, sqzDF, sqzie, UAS-sqz (Allan et al., 2003). UAS-ap and apmd544 (referred to as apGal4)(O'Keefe et al., 1998). aprK568 (referred to as aplacZ)(Cohen et al., 1992). gsb01155 (referred to as gsblacZ) (Duman-Scheel et al., 1997), a marker for neuroblast lineages in rows 5 and