![FBCs dissociate during Ecdysone-regulated FBR to initiate amoeboid swimming cell migration. (A) Schematic showing fat body morphology before, during, and after FBR (third instar larva, prepupa, and 16 h APF pupa). (B and C) Wide-field time-lapse images of the dorsal view of a pupa expressing Lsp2-Gal4+UAS-NLS-mCherry (B1–B5, pupal age 4 h APF at start of movie, imaged at room temperature). Time in hours: min. Migration tracks starting 1 h after head eversion (tracks of minimum length of 90 min): color-coded according to current speed (B4 and B5). Quantification of mean current speed of FBCs in head and thorax over time (C; n: 357 tracks from 6 pupae, black line showing mean and standard deviation shown in blue). See Video 1. (D–F) Wide-field images of the dorsal view of head and thorax region of 16 h APF pupae expressing Lsp2-Gal4+UAS-NLS-mCherry +control (D) or +UAS-EcRDN6869 (E). Quantification of number of FBCs in front of head (F; n: 10 pupae [control], 15 pupae [UAS-EcRDN6869]; cells counted in front half of head [dotted rectangle in D]). Mann–Whitney test, ****P < 0.0001. (G and H) Confocal images of fat body expressing Lsp2-Gal4+UAS-LifeAct-GFP +control (G) and UAS-EcR-DN6869 (H, Z projection top and single Z plane bottom). Scale bars: 300 µm (B), 150 µm (D and E), and 20 µm (G and H).](https://cdn.rupress.org/rup/content_public/journal/jcb/225/3/10.1083_jcb.202504139/1/jcb_202504139_fig6.png?Expires=1771196085&Signature=Aikvd5f9ZEK58k4CYKF55t7YoAdIs3mNd0HWqWq2SFTRiFfwOFl-MEW-QRexiGiAeivpr68a~w5i1QG8msPym3BwKfQ1XWvMybLSOaPeUhB3j9g1PiNYQMc277JZNPjqT4rJ12QpUM9AQOEUjxVvDwR6uHigS8nDCdFTKjx3PUhw~x3ZYhn4YRF9PJ6W0RsDRDwOftWQde7dINqFyK2mgAEup-ZwFudhEg001bQH~1fCOnILIJlWf~We1PG95klrCr13zroVXGhFMXaLmzAgCudrJY9u-Nyn~gUVk8Ee-AOB7ro-AOIXyXN~lMkjVIObwHE9wS~eHqRce9no-wzTyA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
FBCs dissociate during Ecdysone-regulated FBR to initiate amoeboid swimming cell migration. (A) Schematic showing fat body morphology before, during, and after FBR (third instar larva, prepupa, and 16 h APF pupa). (B and C) Wide-field time-lapse images of the dorsal view of a pupa expressing Lsp2-Gal4+UAS-NLS-mCherry (B1–B5, pupal age 4 h APF at start of movie, imaged at room temperature). Time in hours: min. Migration tracks starting 1 h after head eversion (tracks of minimum length of 90 min): color-coded according to current speed (B4 and B5). Quantification of mean current speed of FBCs in head and thorax over time (C; n: 357 tracks from 6 pupae, black line showing mean and standard deviation shown in blue). See Video 1. (D–F) Wide-field images of the dorsal view of head and thorax region of 16 h APF pupae expressing Lsp2-Gal4+UAS-NLS-mCherry +control (D) or +UAS-EcRDN6869 (E). Quantification of number of FBCs in front of head (F; n: 10 pupae [control], 15 pupae [UAS-EcRDN6869]; cells counted in front half of head [dotted rectangle in D]). Mann–Whitney test, ****P < 0.0001. (G and H) Confocal images of fat body expressing Lsp2-Gal4+UAS-LifeAct-GFP +control (G) and UAS-EcR-DN6869 (H, Z projection top and single Z plane bottom). Scale bars: 300 µm (B), 150 µm (D and E), and 20 µm (G and H).