Fig. 1

Progress of early regeneration after oral siphon amputation and branchial sac transcriptome experimental design. A–G The early steps of oral siphon (OS) regeneration. A A month-old unoperated animal showing the OS amputation plane (red dashed line). AS, atrial siphon; BSV, branchial sac vasculature. Red boxes: OS and BSV areas used for quantifying EdU labeling in Figs. 9 and 10. Scale bar: 50 μm. B–G The distal edges of the OS at day 0 in an unoperated animal (B) and at days 1–5 after OS amputation (C–G). OPO, oral siphon pigment organ; CMB, circular muscle band; LMB, longitudinal muscle band. Scale bar: 15 μm; same magnification in B–G. H Diagram illustrating BS isolation and RNA preparation design in day 0 unoperated controls and days 1 and 3 after OS amputation. Micrograph: An isolated BS. OPO, original oral siphon pigment organs; R OPO, regenerating OPO; NC, neural complex; AS, atrial siphon; En, endostyle; V, viscera; BS, branchial sac; TV, transverse vasculature with stem cells