POWRE: Molecular Mechanisms of Thyroid Hormone Action on Stem Cells

9805900 霍斯金斯 在这项由POWRE奖资助的研究中，霍斯金斯博士将研究青蛙眼睛在变态过程中发生变化的分子基础。 小蝌蚪的眼睛位于头部的两侧，两只眼睛观看视觉世界的非重叠区域。 在变态过程中，头部改变形状，眼睛一起移动，结果是成年青蛙具有双眼视觉-视觉世界的一部分可以用两只眼睛看到，就像人类一样。 在甲状腺激素的作用下，从蝌蚪到青蛙的转变过程中，眼睛内部以及眼睛和大脑之间的连接都发生了许多变化。 霍斯金斯实验室先前的工作表明，甲状腺激素诱导视网膜生长的一种特殊的新模式，并且在变态过程中产生了一组新的视神经轴突。 这些新的研究将解决甲状腺激素如何触发视网膜生长变化的问题，以及在变态过程中形成的新轴突如何能够连接到其适当的目标，这与蝌蚪轴突的连接模式不同。 甲状腺激素通过一种能够改变基因表达模式的受体发挥作用;因此，在视网膜中表达的甲状腺激素诱导的基因似乎可能在视觉系统的变态转变中发挥作用。 包括人类在内的所有动物的神经系统都依赖甲状腺激素来正常发育。 霍斯金斯博士的实验系统提供了一个独特的可访问和可操作的模型，用于检查甲状腺激素在发育过程中的作用机制，这些研究的结果预计将与其在神经元发育中的一般作用有关。 这个权力奖将允许一个优秀的调查员与实质性的教学职责，开始一个研究项目，使用新的分子方法论的一个系统和一个问题，她一直有一个长期的兴趣。

9805900 HOSKINS In the study funded by this POWRE award, Dr. Hoskins will examine the molecular basis of changes that occur in the frog eye during metamorphosis. The eyes of young tadpoles are situated on the sides of the head and the two eyes view non- overlapping regions of the visual world. During metamorphosis, the head changes shape, and the eyes move together, with the result that adult frogs have binocular vision -- parts of the visual world are seen with both eyes, as is the case in humans. During the transition from tadpole to frog, which is brought about by thyroid hormone, numerous changes occur both within the eye and in the connections between the eye and the brain. Previous work from the Hoskins laboratory showed that thyroid hormone induces a specific new pattern of retinal growth, and that a new set of optic nerve axons are produced during metamorphosis. These new studies will address the question of how thyroid hormone triggers changes in retinal growth, and how the new axons formed during metamorphosis are able to connect to their proper targets, which differs from the pattern of connections made by tadpole axons. Thyroid hormone acts through a receptor that is capable of changing the pattern of gene expression; it therefore seems likely that hormone-induced genes expressed in the retina will play a role in the metamorphic transformations in the visual system. The nervous systems of all animals, including humans, are dependent on thyroid hormone for proper development. Dr. Hoskins' experimental system offers a uniquely accessible and manipulable model for examining the mechanisms of thyroid hormone action during development, and the results of these studies are expected to be relevant to its general roles in neuronal development. This POWRE award will allow an excellent investigator with substantial teaching duties to begin a research project using new molecular methodology on a system and a question with in which she has had a long -standing interest.