功能探讨蝙蝠高频听力基因prestin的分子进化机制和回声定位起源
文献类型：学位论文
| 作者 | 祁飞燕 |
| 学位类别 | 硕士 |
| 答辩日期 | 2014-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 施鹏 |
| 关键词 | 蝙蝠 高频听力 回声定位 prestin 点突变 共同祖先 序列重建 趋同进化 平行进化 |
| 其他题名 | Functional evidence for molecular basis and origin of high frequency hearing adaptive evolution in bat |
| 学位专业 | 遗传学 |
| 中文摘要 | 高频听力是蝙蝠利用回声定位进行捕食，定位和航行所必需的，但并不是所有的蝙蝠都有回声定位这一特性。大多数蝙蝠除了大蝙蝠超科（Pteropodidae）以外都利用回声定位适应黑暗夜空这一独特的生态位。另外，与蝙蝠有不同生活环境的齿鲸也是凭借能听到高频听力而利用回声定位来适应光线昏暗的水下环境，二者在回声定位这一功能性状上发生了适应性趋同进化。对这个性状的趋同的研究，先前的研究主要集中在回声定位哺乳动物中与高频听力相关的基因的平行进化位点的分子水平研究，但是对于高频听力这一个因适应环境而进化出来的功能性状，在功能水平上的研究仍是个缺口。本研究结合分子和功能实验出发探索利用回声定位适应环境的蝙蝠和齿鲸在高频听力适应性进化上是否具有相同的分子机制？并将第一个确认与回声定位高频听力相关的听力基因prestin作为本研究的候选基因。通过功能结果分析，我们发现回声定位哺乳动物虽然在prestin功能上有趋同但是在功能结果NLC的不同参数上却表现出不同。进一步研究发现在prestin上存在相关的趋同位点导致功能上的差异。本研究首次揭示了回声定位哺乳动物中与回声定位相关基因的功能模式，以及进一步揭示了影响prestin功能的趋同位点的不同作用，为哺乳动物回声定位分子机制的研究提供了新的思路。同时，基于并非所有蝙蝠都有回声定位这一前提，为了探索回声定位高频听力在蝙蝠中经历了几次起源的问题，我们构建了蝙蝠共同祖先prestin序列，并通过功能验证，我们发现蝙蝠共同祖先可能已经获得了高频听力的能力，且在共同祖先prestin氨基酸序列上发现了两个可能使得蝙蝠共同祖先获得高频听力的氨基酸位点，因此我们的结论进一步支持了蝙蝠回声定位一次起源的假说。本研究结合共同祖先氨基酸序列的重建，首次从功能出发来探讨蝙蝠回声定位起源的历史进化争议问题，也为研究共同祖先功能状态的问题提出了新的方法. |
| 英文摘要 | High frequency hearing is necessary for bats to prey, orientation and navigation when the echolocation is used. Although echolocation is usually associated with bats, it is not the characters of all bats. Most bats take advantage of echolocation to adapt the unique niche of dark sky except the Pteropodidae. Otherwise, tooth whales also have echolocation to adapt underwater environment where lack of light. So, echolocation bats and tooth whale had convergent evolution in phenotype of echolocation, and this yield out two questions: one is that did bats and tooth whale own same molecular mechanism to adapt the similar environment? And another question is that did bats achieve the echolocation which had relationship with high hearing frequency in the initial ancient of bats or evolved independently in microbats? Previous studies have focused on the morphological and molecular data to resolve these questions. It still is a gap to solve these questions using functional evidence. In this paper, we combine molecular data and functional evidence to try to resolve these questions. In our study, we chose prestin as our candidate gene which has been identified as a hearing gene and has close relationship to high frequency hearing. Our result comes from site mutation and functional experiments indicate that echolocating mammals went through the convergent evolution in function of prestin, and divergence in different parameters, which are also correlated with mammalian high-frequency hearing. Furthermore, we found that the some convergent sites of prestin between echolocating mammals caused the functional divergence due to the interactions between sites. To our knowledge, these findings for the first time present the functional patterns of echolocation-related genes in echolocating mammals and reveal the different roles of convergent sites for prestin function, paving the way to insights into the molecular mechanism underlying mammalian echolocation. Similarly, to solve the controversial question about did echolocation evolved once or more than once we reconstructed bats ancestors prestin sequences? Combine with functional data we found the echolocation of bats probably achieved since the origin of bats evolved. Fortunately, two parallel evolution sites were found in bat common ancestor prestin sequence, and we induce these two sites are the molecular bases of bats common ancestor achieved the ability of echolocation. This study is the first time to shed light on the origin of echolocation with functional evidence. Considering lack of fossil evidences, ancestral sequences reconstruction and function terrifying provide a novel approach to study the ancestor hearing of bats. |
| 语种 | 中文 |
| 公开日期 | 2014-07-04 |
| 源URL | [http://159.226.149.42:8088/handle/152453/7934]  |
| 专题 | 昆明动物研究所_进化与功能基因组学 |
| 推荐引用方式 GB/T 7714 | 祁飞燕. 功能探讨蝙蝠高频听力基因prestin的分子进化机制和回声定位起源[D]. 北京. 中国科学院研究生院. 2014. |
入库方式： OAI收割
来源：昆明动物研究所
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