10.6084/m9.figshare.5999777.v1
Melissa Cui Bender
Melissa Cui
Bender
Caroline Hu
Caroline
Hu
Chris Pelletier
Chris
Pelletier
Robert J. Denver
Robert J.
Denver
Supplemental Methods 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
The Royal Society
2018
metamorphosis
tadpole
feeding behaviour
leptin
2018-03-19 14:28:25
Journal contribution
https://rs.figshare.com/articles/journal_contribution/Supplemental_Methods_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/5999777
Many animal life histories entail changing feeding ecology, but the molecular bases for these transitions are poorly understood. The amphibian tadpole is typically a growth and dispersal life-history stage. Tadpoles are primarily herbivorous, and they capitalize on growth opportunities to reach a minimum body size to initiate metamorphosis. During metamorphic climax, feeding declines, at which time the gastrointestinal tract (GI) remodels to accommodate the carnivorous diet of the adult frog. Here we show that anorexigenic hypothalamic feeding controls are absent in the tadpole, but develop during metamorphosis concurrent with the production of the satiety signal leptin. Before metamorphosis there is a large increase in <i>leptin</i> mRNA in fat tissue. Leptin receptor mRNA increased during metamorphosis in the preoptic area/hypothalamus, the key brain region involved with the control of food intake and metabolism. This corresponded with an increase in functional leptin receptor, as evidenced by induction of <i>socs3</i> mRNA and phosphorylated STAT3 immunoreactivity, and suppression of feeding behaviour after injection of recombinant frog leptin. Furthermore, we found that immunoneutralization of leptin in tadpoles at metamorphic climax caused them to resume feeding. The absence of negative regulation of food intake in the tadpole allows the animal to maximize growth prior to metamorphosis. Maturation of leptin-responsive neural circuits suppresses feeding during metamorphosis to facilitate remodelling of the GI.