Functional Analysis of Even-Skipped Regulatory Evolution

偶数跳跃监管演化的功能分析

• 批准号: 9982715
• 负责人: Martin Kreitman
• 金额: $ 54.21万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9982715&HistoricalAwards=false
• 关键词: Functional; Analysis; Even; Skipped; Regulatory

Research into the structure/function relationship and the evolution of the even-skipped stripe two (eve stripe 2) element of Drosophila melanogaster, arguably the best characterized of all eukaryotic regulatory elements will be continued. Considerable evolutionary change has occurred in the eve stripe 2 element including changes in functionally important binding sites for trans-acting transcription factors. Novel binding sites can be seen to emerge de novo and pre-existing sites can be seen to disappear. The length of stripe 2 element also evolves, thus changing the spacing between transcription factor binding sites. Yet despite these structural changes the stripe 2 elements from several different species, when placed in D. melanogaster, express a reporter gene at identical and indistinguishable times and locations as the native eve stripe 2. Thus functional conservation is maintained despite structural change in the architecture of the element, a strong indication that stabilizing selection is the dominant mode of selection governing this element's evolution. However a chimeric eve stripe 2 element composed of the left and right halves of two functionally conserved elements does not express correctly and raises the possibility that epistatic changes are involved in maintaining functional stasis in the native element. The specific aims of this work are:1. To further investigate functional differences in native and chimeric eve stripe 2 elements by phenotypic analysis in late embryos, larvae and adults using two different "rescue" techniques2. To initiate functional studies of evolved differences in bicoid and kruppel binding sites in the melanogaster subgroup species to determine if compensatory evolution has also occurred in these regulatory loci3. To quantitate expression levels of a lacZ reporter gene when driven by native and chimeric eve stripe 2 elements from different species of Drosophila and to determine the molecular basis of evolved differences in those levels 4. To evaluate the generality of results by conducting comparative sequence analysis in other Drosophila species as well as in the mosquito and housefly.The long-term objective of the proposed research is to understand cis-regulatory sequence evolution in eukaryotes, including the mutational and functional mechanisms by which regulatory evolution occurs and the selective and non-selective forces at work. Deciphering the rules governing the evolution of regulatory sequence evolution is likely to benefit efforts to decode whole genome sequences, including humans and therefore is expected to have a major impact on advancing knowledge in experimental and computational genomics. It will also serve as fertile training ground in these important new areas of biological science.

对果蝇的偶数跳跃条纹2(Eve条纹2)元件的结构/功能关系和进化的研究将继续下去，该元件被认为是所有真核调控元件中最具特征的。EVESTRIPE 2元件发生了相当大的进化变化，包括功能上重要的反式转录因子结合位点的变化。可以看到新的结合位点从头开始出现，可以看到先前存在的结合位点消失。条纹2元件的长度也会进化，从而改变转录因子结合位点之间的间距。然而，尽管这些结构发生了变化，来自几个不同物种的条纹2元件，当被放入黑腹圆锥菌中时，表达报告基因的时间和位置与原生的夏娃条纹2相同且难以区分。因此，尽管元件的结构发生了变化，但功能保持不变，这有力地表明，稳定选择是支配该元件进化的主要选择模式。然而，由两个功能保守的元件的左右半部分组成的嵌合的前夕条纹2元件不能正确表达，并增加了上位性变化参与维持天然元件功能停滞的可能性。本研究的具体目的是：1.利用两种不同的“挽救”技术，通过表型分析进一步研究天然和嵌合EV2基因在胚胎、幼虫和成虫中的功能差异。启动对黑胃动物亚群物种中双核和Kruppel结合位点进化差异的功能研究，以确定这些调节基因是否也发生了代偿进化3。4.通过对其他果蝇物种以及蚊子和家蝇中的LacZ报告基因进行比较序列分析，以评估结果的普遍性。本研究的长期目标是了解真核生物中顺式调控序列的进化，包括调控进化发生的突变和功能机制，以及选择性和非选择性力量的作用。破译调控序列进化的规则可能有助于破译包括人类在内的整个基因组序列，因此有望对推进实验和计算基因组学的知识产生重大影响。它还将在这些重要的生物科学新领域中充当肥沃的训练场。