Dissertation Research: Evaluating the role of thyroid hormone in embryonic limb development in direct-developing frogs

论文研究：评估甲状腺激素在直接发育的青蛙胚胎肢体发育中的作用

• 批准号: 1701591
• 负责人: James Hanken
• 金额: $ 2.19万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701591&HistoricalAwards=false
• 关键词: Dissertation; Research; Evaluating; role; thyroid

This study will clarify the role of thyroid hormone in the development of amphibian limbs. Hormones are substances produced in the body that influences the way the body grows or develops. Thyroid hormone plays an important role in the transition of tadpoles into frogs, especially in limb development. Nearly a third of frog species bypass the tadpole stage and develop directly into frogs and the role of thyroid hormone in the development of these species is not known. This project will test two alternative hypotheses about the role of thyroid hormone in this process. In association with the Harvard Museum of Natural History, this project will also develop several educational activities on amphibian biodiversity for K-12 students, teachers, and parents. Some of these activities can be offered at little cost, which will allow many students to experience wildlife and witness the dramatic transformation of metamorphosis for themselves.Comparing how thyroid hormone regulates gene activity during limb development between direct-developing and metamorphosing frogs can tell us how fundamental endocrine networks evolve and generate different life cycles. Biphasic frogs (which undergo metamorphosis) require thyroid hormone (TH) for metamorphosis and limb development. This study evaluates the role of TH in limb development in the direct-developing frog Eleutherodactylus coqui for comparison to its role in three biphasic frog taxa (Xenopus laevis, Bombina orientalis, and Dendrobates tinctorius). Next-generation sequencing will be used to characterize and compare the TH-induced molecular phenotype in the developing limb of all four species. This study will provide a basis for further studies of amphibian life history evolution and identify interspecific variation in an otherwise highly conserved molecular mechanism of metamorphosis. Characterizing how one group achieves direct development will provide a comparison for investigating the repeated origins of this life history in other amphibians, and address questions at the intersection of endocrinology, evolution, and development.

这项研究将阐明甲状腺激素在两栖动物四肢发展中的作用。激素是体内产生的物质，会影响人体成长或发展的方式。甲状腺激素在t骨向青蛙的过渡中起着重要作用，尤其是在肢体发育中。近三分之一的青蛙物种绕过t阶段并直接发展为青蛙，甲状腺激素在这些物种的发展中的作用尚不清楚。该项目将测试有关甲状腺激素在此过程中的作用的两个替代假设。与哈佛大学自然历史博物馆联合，该项目还将针对K-12学生，老师和父母开展几项有关两栖动物生物多样性的教育活动。这些活动中的某些活动几乎无法成本提供，这将使许多学生能够体验野生动植物，并见证甲状腺激素如何调节甲状腺激素在直接开发和变质蛙之间如何调节基因活性的急剧转变。双相青蛙（发生变态）需要甲状腺激素（Th）来进行变态和肢体发育。这项研究评估了TH在肢体发育中的作用在直接开发的青蛙Eletherodactylus coqui中，以与其在三个双相青蛙分类群（Xenopus laevis，Bombina orientalis和Dendrobates Tinctorius）中的作用进行比较。下一代测序将用于表征和比较所有四个物种发育中的肢体中Th诱导的分子表型。这项研究将为两栖动物的生命历史进化提供进一步研究的基础，并确定原本高度保守的变态分子机制中种间变异。表征一个群体如何实现直接发展的方式将提供一个比较，以调查其他两栖动物中这种生活史的重复起源，并在内分泌学，进化和发展的交集中解决问题。

项目成果

Environmental Oxygen Exposure Allows for the Evolution of Interdigital Cell Death in Limb Patterning

• DOI: 10.1016/j.devcel.2019.05.025
• 发表时间: 2019-07-22
• 期刊: DEVELOPMENTAL CELL
• 影响因子: 11.8
• 作者: Cordeiro, Ingrid Rosenburg;Kabashima, Kaori;Tanaka, Mikiko
• 通讯作者: Tanaka, Mikiko

Evolutionary Conservation of Thyroid Hormone Receptor and Deiodinase Expression Dynamics in ovo in a Direct-Developing Frog, Eleutherodactylus coqui

• DOI: 10.3389/fendo.2019.00307
• 发表时间: 2019-05-24
• 期刊: FRONTIERS IN ENDOCRINOLOGY
• 影响因子: 5.2
• 作者: Laslo, Mara;Denver, Robert J.;Hanken, James
• 通讯作者: Hanken, James