DISSERTATION RESEARCH: The genome-wide occupancy and thermosensitivity of histone variant H2A.Z in embryonic Chrysemys picta, a turtle with temperature-dependent sex determination

在大多数动物中，后代的性别由其遗传构成决定(遗传型性别决定，GSD)，而在其他动物中，它由发育过程中的孵化温度决定(温度依赖的性别决定，TSD)。在TSD中，对雄性或雌性形成至关重要的基因会根据温度而开启或关闭，但温度起作用的确切分子机制仍不清楚。该项目的目标是验证这样一种假设，即已知在植物和真菌中具有温度敏感性的DNA结合蛋白H2A.Z在TSD脊椎动物中也是温度敏感的，并负责使DNA或多或少能够被激活，从而将温度信号转化为差异基因表达。利用彩绘龟甲(TSD)和下一代DNA测序技术，将在整个海龟基因组中定位与DNA结合的H2A.Z的位置和温度敏感性。这个项目提出了一个关于动物如何感知和对温度做出反应的新假说，如果这是真的，可能会改变我们对TSD脊椎动物性别决定的理解，以及温度如何影响整个脊椎动物的发育。这个项目为本科生的研究提供了许多机会，PI和Co-PI都致力于为科学中代表性不足的群体提供教育和研究经验。Co-Pi也是NSF GK-12研究员，将科学教育带到当地中学课堂和公共演讲活动中。

In most animals, the sex of the offspring is determined by its genetic constitution (Genotypic Sex Determination, GSD) while in others it is determined by the incubation temperature during development (Temperature-dependent Sex Determination, TSD). In TSD, genes important for the formation of males or females are switched on/off depending on the temperature, but the exact molecular mechanism by which temperature operates remains unknown. The goal of this project is to test the hypothesis that H2A.Z, a DNA-binding protein known to be thermosensitive in plants and fungi, is also thermosensitivity in TSD vertebrates and responsible for making the DNA more or less accessible to activation, thus translating the temperature signal into differential gene expression. Using the painted turtle Chrysemys picta (TSD) and Next-Generation DNA Sequencing technology, the location and thermosensitivity of H2A.Z binding to DNA will be mapped across the turtle genome. This project proposes a novel hypothesis about how animals sense and respond to temperature, which if true, could transform our understanding both how sex is determined in TSD vertebrates, and how temperature affects overall vertebrate development. This project provides many opportunities for undergraduate research, and both the PI and Co-PI are committed to providing educational and research experiences to underrepresented groups in science. The Co-PI is also an NSF GK-12 Fellow, bringing science education to local middle school classrooms and public speaking events.