Thyroid Hormone-Dependent Metamorphosis in a Direct Developing Frog

The direct developing anuran, Eleutherodactylus coqui, lacks a tadpole, hatching as a tiny frog. We investigated the role of the metamorphic trigger, thyroid hormone (TH), in this unusual ontogeny. Expression patterns of the thyroid hormone receptors, TRα and TRβ , were similar to those of indirect...

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Veröffentlicht in:Proceedings of the National Academy of Sciences - PNAS 2000-03, Vol.97 (6), p.2615-2620
Hauptverfasser: Callery, E M, Elinson, R P
Format: Artikel
Sprache:eng
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Zusammenfassung:The direct developing anuran, Eleutherodactylus coqui, lacks a tadpole, hatching as a tiny frog. We investigated the role of the metamorphic trigger, thyroid hormone (TH), in this unusual ontogeny. Expression patterns of the thyroid hormone receptors, TRα and TRβ , were similar to those of indirect developers. TRβ mRNA levels increased dramatically around the time of thyroid maturation, when remodeling events reminiscent of metamorphosis occur. Treatment with the goitrogen methimazole inhibited this remodeling, which was reinitiated on cotreatment with TH. Despite their radically altered ontogeny, direct developers still undergo a TH-dependent metamorphosis, which occurs before hatching. We propose a new model for the evolution of anuran direct development.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.050501097