Frog serum and estrogen promote re-epithelialisation and proliferation in <i>Xenopus tropicalis</i> skin.

<p>(<b>A</b>) Representative images of re-epithelialisation sheet in control, 5% frog serum and 100 nM 17β-estradiol (Est)-treated punch wounds at day 7 in culture (scale bars: 0.5 mm). White-hatched lines indicate the leading edge of new epithelial sheets. (<b>B</b>) Representative images of PH3-positive cells in control, 5% frog serum and 100 nM 17β-estradiol-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) Representative images of TUNEL-positive cells in control, 5% frog serum and 100 nM 17β-estradiol-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. Scale bars in (<b>B</b>) and (<b>C</b>) are 100 µm. (<b>D</b>) The graph shows the percentage reduction in wound-area of <i>Xenopus tropicalis</i> punch wounds in control, 5% frog serum (FS) and 100 nM 17β-estradiol-treated skin. (<b>E</b>) Percentage of proliferative (PH3-positive) cells present in the new epithelial tongue during re-epithelialisation. (<b>F</b>) Percentage of apoptotic (TUNEL-positive) cells present in the new epithelial tongue during re-epithelialisation. Data are mean ± SEM of 4–5 frogs (2 male and 3 female). Significance relative to control data at the same time-point denoted by *P<0.05, **P<0.01, ***P<0.001.