Differential thyroid hormone sensitivity of fast cycling progenitors in the neurogenic niches of tadpoles and juvenile frogs.

摘要: Adult neurogenesis occurs in neural stem cell (NSC) niches where slow cycling cells give rise to faster progenitors. In the adult mouse NSC niche thyroid hormone, T3, and its receptor TRα act as a neurogenic switch promoting progenitor cycle completion neuronal differentiation. Little is known about whether how T3 controls proliferation of differentially during xenopus neurogenesis. To address this question, we first used Sox3 marker populations then applied pulse-chase EdU/IdU incorporation experiments identify Sox3-expressing fast cells. We focused on lateral ventricle Xenopus laevis two distinct stages development: late embryonic development (pre-metamorphic) juvenile frogs (post-metamorphic). These were selected for their relatively stable hormone availability, either side major dynamic phase represented by metamorphosis. expression was found both pre post-metamorphic regions. However, exogenous treatment only increased Sox3+ population juveniles, having no detectable effect pre-metamorphic tadpoles. hypothesised that resistance proliferative tadpoles could be related inactivation inactivating Deiodinase 3 enzyme. Expression dio3 widespread tadpole niche, but not niche. Use T3-reporter transgenic line showed had direct transcriptional rapid Thus, respond function developmental stage.