Supplemental Fig. 4 from To eat or not to eat: ontogeny of hypothalamic feeding controls and a role for leptin in modulating life-history transition in amphibian tadpoles

Functional leptin signaling in tadpole pituitary increased during metamorphosis. We investigated changes in functional leptin signaling in the tadpole pituitary gland brain during metamorphosis by analyzing rxLeptin-induced phospho-STAT3 immunoreactivity (pSTAT3-ir). A. The arrow on the anatomical drawing of the dorsal view of Xenopus brain shows the location of the transverse section shown at right, after Tuinhof et al. [1]. Abbreviations: tect – optic tectum, tegm – mesencephalic tegmentum, TP – posterior tuberculum, pd – pars distalis, pi – pars intermedia, pn – pars nervosa. B. Tadpoles were given i.c.v. injections of 0.6% saline or rxLeptin (20 ng/g*BW) and killed one hr later for immunohistochemistry for pSTAT3-ir (see Supplemental Methods). The scale bar equals 50 m and applies to all photomicrographs in the panels. C. Changes in mean nuclei count of pSTAT3-ir cells in the tadpole pars distalis during metamorphosis. We counted the number of pSTAT3-ir nuclei following i.c.v. injection of rxLeptin as described in the Materials and Methods. Shown are the means±SEM (n=3-4/developmental stage). We saw statistically significant changes in pSTAT3-ir in the pars distalis during metamorphosis (F(4,12)=10.211, p=0.001; ANOVA). Means with the same letter are not significantly different (p<0.05; Fisher’s LSD test).