Movie 1.

Stability of Musclebow labelling on short timescales. Tg(BB3mus7)^kg309; Tg(HS:Cre.cryaa:RFP)^kg310 embryo was subjected to 5 min heat-shock at 30% epiboly. After embedding in 3% methylcellulose with light tricaine at 26 hpf, 15 sequential confocal time-lapse 3-colour 3-tile 2 μm stacks were taken every 24 min over 6 h at 24°C. An 11-slice mip of each stack is shown.