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.

本研究将阐明甲状腺激素在两栖动物肢体发育中的作用。激素是体内产生的物质，影响身体生长或发育的方式。甲状腺激素在蝌蚪向青蛙的转变中发挥着重要作用，尤其是在肢体发育中。近三分之一的青蛙物种绕过蝌蚪阶段，直接发育成青蛙，甲状腺激素在这些物种发育中的作用尚不清楚。这个项目将测试两个关于甲状腺激素在这一过程中的作用的替代假设。该项目还将与哈佛自然历史博物馆合作，为K-12学生、教师和家长开发几项关于两栖动物生物多样性的教育活动。其中一些活动可以以很低的成本提供，这将使许多学生体验野生动物，亲眼目睹变态的戏剧性转变。比较甲状腺激素如何调节直接发育和变态青蛙肢体发育期间的基因活性，可以告诉我们基本的内分泌网络是如何进化和产生不同的生命周期的。双相蛙（经历变态）需要甲状腺激素（TH）进行变态和肢体发育。本研究评估TH在肢体发育中的作用，在直接发展的青蛙Eleutherodactylus coqui比较其作用在三个两相青蛙类群（非洲爪蟾，铃蟾东方，和Dendrobates tinctorius）。下一代测序将用于表征和比较所有四个物种发育肢体中TH诱导的分子表型。本研究将为进一步研究两栖动物的生活史进化和鉴定一种高度保守的变态分子机制的种间变异提供基础。描述一个群体如何实现直接发展将为调查其他两栖动物这种生活史的重复起源提供比较，并解决内分泌学，进化和发展交叉点的问题。

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