Figure 5.

KD of RpL13 in Drosophila heart leads to absence of the heart. KD of the ribosomal subunit RpL13 in the fly heart leads to complete loss of the heart in adults as visualized by brightfield microscopy (A, B) as well as actin staining using fluorescently tagged phalloidin (C, D). Absence of the heart was also observed in 3rd instar larvae (E, F). Embryonic dorsal mesoderm expression of RpL13 RNAi using the TinD-GAL4; midline-GFP driver (26–28) led to a mostly absent heart with posterior remnants that were constricted (G,H). Using a temperature sensitive driver (HTT; Hand4.2-GAL4, Tubulin-GAL80^ts, Tubulin-GAL80^ts) (54) to regulate Hand4.2-GAL4 KD of RpL13 allowed us to temporally regulate RpL13 expression during development. RpL13-RNAi expression during embryonic and early L1-larval stages resulted in a no-heart phenotype (I), while RpL13-RNAi expression starting at L1 larval stages through adult eclosion did not lead to any loss of heart structure (J), suggesting a developmental role for RpL13 specifically during embryonic stages. Asterisk denotes absent heart structures.