Figure 2. Cycling somatic cells are distributed throughout the tapeworm body and are irradiation sensitive.

(a-b) Maximum-intensity projections of confocal sections showing distribution of cycling cells by 2 hr uptake of F-ara-EdU (a) or FISH for mcm2 (b). Fewer cycling cells were found in the head (box), while abundant cycling cells were observed in both somatic and gonadal tissues throughout the body. t = testis, o = ovary. (c) Maximum-intensity projections of tile-stitched confocal sections after 1 hr uptake of F-ara-EdU (green) 3 days post-irradiation. (d) Quantification of F-ara-EdU⁺ cell inhibition from (c). Error bars = SD, N = 2, n = 11 and 9, Student’s t-test. (e) RNA-seq strategy to identify genes expressed in cycling cells. (Nuclei are counterstained with DAPI (gray) in this and all subsequent figures.).

Figure 2—figure supplement 1. Irradiation inhibits tapeworm regeneration.

(a) DAPI staining of 5 mm anterior fragments from control and irradiated worms before and after 6 days in vitro culture. (b) Quantification of (a). Error bars = SD, N = 2, n = 10–16, one-way ANOVA with Tukey’s multiple comparison test. (c–d) Lethal dose of irradiation was revealed when 5 mm anterior fragments were amputated and grown in vitro for 1 month from worms exposed to 0 Gy or 200 Gy x-irradiation. The irradiated samples in (d) are shown to scale as an inset in (c).

Figure 2—figure supplement 2. Validation of RNA-seq by WISH after irradiation.

WISH (with Fast-Blue Development) from two regions of the tapeworm: anterior (left) and body (right), 3 days post-irradiation.