Fig. 4. Hakai, Vir, Fl(2)d, and Flacc form a stable complex.

In wild-type wing discs, Fl(2)d (a), Nito (a’), Flacc (b), and Vir (c) show ubiquitous nuclear staining patterns. g–l Expressing Hakai RNAi in the dorsal half of the disc (below the dashed line) using ap-Gal4 resulted in a strong reduction of Fl(2)d (h, squared areas are magnified on the right), Vir (h’), and Flacc (i) levels, but not Mettl3 (j), Mettl14 (k), and Nito staining (l). f–f’ Fl(2)d staining is similarly reduced in Hakai mutant clones generated by actin-Cas9/U6-Hakai-sgRNA (f), which are marked by the loss of Hakai staining (f’). m–r Expressing vir RNAi in the dorsal half of the disc (below the dashed line) using ap-Gal4 resulted in a strong reduction of Fl(2)d (n), Hakai (o), and Flacc (p) levels, but not Mettl3 (q), Mettl14 (n’), and Nito staining (r). s–x Expressing fl(2)d RNAi in the dorsal half of the disc (below the dashed line) using ap-Gal4 resulted in a strong reduction of Hakai (t), Vir (u), and Flacc (v) levels, but not Mettl3 (s’), Mettl14 (w), and Nito staining (x). d, e Expressing Flacc RNAi in the dorsal half of the disc (below the dashed line) using ap-Gal4 led to more diffusive and less nuclear staining of Fl(2)d (e, squared areas are magnified on the right). The experiments in a–x were repeated at least twice independently with similar results, and each time around 30 wing discs for any genotype were examined. Scale bars: 10 μm. y A working model of the m⁶A writer complex comprised of seven core components.