(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 3. Histology and cytochemistry of extirpated buds and degenerating zooids
isolated from Botryllus schlosseri colonies. (AC) An
epithelial monolayer that developed from an isolated zooid in mid-takeover,
14-day culture period (A, x200; B, x400). At 3 weeks incubation
(C, x200), the monolayer has started to deteriorate. TUNEL assay did not
reveal positive nuclei. (D) An epithelial monolayer originated from stage `C'
bud (x200) at the deteriorating stage, 4 weeks in culture. TUNEL assay
performed on this monolayer did not reveal positive nuclei. (E,F) Apoptotic
cells in histological section carried out on the extirpated stage `D' and
TUNEL-stained zooid (E, x200); also stained for general morphology by
Azan (F, x200). (G,H) TUNEL-positive cells (arrowhead) in histological
sections of 5-week old cultured buds, counterstained by Methyl Green (G,
x1000; H, whole bud, x200). cb, cell boundary; dv, disintegrated
visceral organs; e, epithelium; me, monolayer edge; s, stomach; v, vacuole;
vo, visceral organ; n, nucleus. Scale bars, 50 µm.