SG: An experimental test of the role of chromosomal inversions in adaptive evolution

当生物体在其染色体中繁殖和复制DNA时，DNA序列的区域可以相对于原始染色体的区域反转。后代继承了带有原始或反向序列的染色体的拷贝。在某些自然种群中，倒位染色体可以大量分布。这表明它们可能赋予拥有它们的生物体一种优势。这项研究将为一个重要的假设提供第一个实验测试，该假设将解释为什么这些DNA逆转可以增殖。 反转通常具有很大的影响，在许多物种中很常见，包括人类。了解它们的持久性和传播对于基础研究和包括医学和农业在内的应用研究都很重要。该项目还将支持在线工具的开发，以帮助在高中水平教授基本的遗传学和进化原理。十年前，柯克帕特里克-巴顿数学模型被提出来解释自然选择如何允许新的倒位在自然种群中传播。虽然从未得到实验验证，但这个模型已经被用来解释各种物种中反转的传播。该项目将使用果蝇种群对该模型进行实验测试。研究人员将使用基因组编辑工具来实验性地创建一个反转，该反转捕获已知与适应特定环境相关的等位基因。研究人员将监测染色体倒位在重复实验群体中传播的速度，并将此速度与详细的模型预测进行比较。结果应该提供一个强有力的实验证实这个流行的模型或识别偏差，这将建议重新思考如何和为什么染色体倒位在自然种群中传播。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

As organisms reproduce and replicate the DNA in their chromosomes, regions of DNA sequence can get reversed relative to that of the original chromosome. Offspring inherit copies of the chromosomes bearing the original or the inverted sequence. In some natural populations, inverted chromosomes can become abundantly distributed. This suggests that they may confer an advantage to the organism that has them. This research will provide the first experimental test of an important hypothesis that would explain why these DNA reversals can proliferate. Inversions often have large effects and are common in many species, including humans. Understanding their persistence and spread is important to basic research and applied research including medicine and agriculture. This project will also support the development of online tools to help teach basic genetics and evolution principles at the high school level.A decade ago, the Kirkpatrick-Barton mathematical model was proposed to explain how natural selection would allow new inversions to spread in natural populations. Although never experimentally verified, this model has been invoked to explain the spread of inversions in a wide variety of species. This project will experimentally test this model using populations of Drosophila melanogaster fruit flies. The researchers will use genome editing tools to experimentally create an inversion that captures alleles known to be associated with adaptations to particular environments. The researchers will monitor the pace with which the chromosomal inversion spreads in replicated experimental populations and compare this pace to detailed model predictions. The results should either provide a strong experimental confirmation of this popular model or identify deviations that would suggest a rethinking of how and why chromosomal inversions spread in natural populations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.