Collaborative Research: SG: Genomic and functional tests of mitochondrial-nuclear coevolution

合作研究：SG：线粒体-核协同进化的基因组和功能测试

• 批准号: 1753851
• 负责人: Maurine Neiman
• 金额: $ 10万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753851&HistoricalAwards=false
• 关键词: Collaborative; Research; SG; Genomic; functional

Harmful mutations can negatively affect gene, protein, and organism function. In the extreme, the accumulation of harmful mutations can lead to population extinction. The genetic information in mitochondria - the main source of energy production in most complex organisms - is usually passed intact from parents to offspring. Thus, the mitochondria should be especially prone to the buildup of harmful mutations. However, mitochondria have maintained their function for more than one billion years; how and why is an important question in evolutionary biology. This research uses a model snail system to address these questions. It takes advantage of the fact that some lineages of snails pass both their nuclear and mitochondrial genomes on to their offspring without any genetic shuffling; a process that accelerates the accumulation of mutations in these snails. By contrast, there is shuffling of genetic material between parents and offspring in other lineages of the same snail species. This project will compare different lineages of snails, some with genetic shuffling and some without. In doing so, this research will explore how harmful mutations are cleared from populations. Reducing the impact of harmful mutations is important for keeping organisms healthy. In turn, healthy organisms can guard against population extinction. It is possible that harmful mutations in the mitochondria are compensated for by mutations in nuclear genes. This hypothesis will also be tested by this research. Because functional mitochondria are important to the health of many organisms, the research will be relevant to the biomedical and agricultural communities. The research will also train a new generation of scientists and broaden participation in biology. The broader impacts include collaborations with high school students and museums. The project will also extend an award-winning partnership with the National Center for Science Education to new audiences.The research combines genetic and functional methods to test for signatures of mitochondrial-nuclear coevolution in the New Zealand freshwater snail Potamopyrgus antipodarum. In this snail system, some lineages are sexual and others are asexual. Crucially for this study, the asexual lineages of P. antipodarum have higher mitochondrial substitution rates than the sexual lineages. This contrast in mitochondrial substitution rates permits the study's two objectives. Objective 1 will test the hypothesis that higher mitochondrial substitution rates in asexual versus sexual lineages drive stronger mitochondrial-nuclear molecular coevolutionary dynamics. One prediction of these coevolutionary dynamics is that substitution rates for proteins encoded by the nuclear genome that are then targeted to the mitochondria will be higher than the substitution rates in control nuclear gene sets. Objective 2 will test for functional effects of mitonuclear interactions on mitochondrial respiration and snail metabolic rate. Since temperature can impact snail metabolic rates, the second objective will include four different temperature treatments. Results of this research will contribute to our understanding of the mitochondrial-nuclear interactions that define eukaryotes. Furthermore, they are of broad relevance to genome evolution, speciation, and the functional and evolutionary consequences of reproductive mode variation.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.

有害突变会对基因、蛋白质和机体功能产生负面影响。在极端情况下，有害突变的积累可能导致种群灭绝。线粒体是大多数复杂生物体产生能量的主要来源，其遗传信息通常完好无损地从父母传给后代。因此，线粒体应该特别容易产生有害的突变。然而，线粒体已经维持了超过10亿年的功能；如何以及为什么是进化生物学中的一个重要问题。本研究使用一个模型蜗牛系统来解决这些问题。它利用了这样一个事实，即一些蜗牛谱系将其核基因组和线粒体基因组传递给后代，而不进行任何基因重组；这个过程加速了这些蜗牛体内突变的积累。相比之下，在同一种蜗牛的其他世系中，父母和后代之间存在遗传物质的洗牌。这个项目将比较不同的蜗牛血统，一些有基因重组，一些没有。在此过程中，这项研究将探索有害突变是如何从人群中清除的。减少有害突变的影响对保持生物体健康很重要。反过来，健康的生物体可以防止种群灭绝。线粒体中的有害突变可能通过核基因的突变得到补偿。这一假设也将在本研究中得到验证。由于功能性线粒体对许多生物体的健康至关重要，因此该研究将与生物医学和农业社区相关。这项研究还将培养新一代科学家，并扩大生物学的参与范围。更广泛的影响包括与高中生和博物馆的合作。该项目还将把与国家科学教育中心的获奖伙伴关系扩展到新的受众。该研究结合了遗传学和功能方法来测试新西兰淡水蜗牛Potamopyrgus antipodarum线粒体-核共同进化的特征。在这个蜗牛系统中，有些世系是有性的，有些世系是无性的。对于这项研究至关重要的是，P. antipodarum的无性谱系比有性谱系具有更高的线粒体替代率。线粒体替代率的这种对比使研究的两个目标得以实现。目的1将验证在无性谱系和有性谱系中较高的线粒体替代率驱动更强的线粒体-核分子协同进化动力学的假设。这些共同进化动力学的一个预测是，由核基因组编码的蛋白质的替代率，然后靶向线粒体，将高于对照核基因组的替代率。目的2将测试线粒体核相互作用对线粒体呼吸和蜗牛代谢率的功能影响。由于温度会影响蜗牛的代谢率，第二个目标将包括四种不同的温度处理。这项研究的结果将有助于我们对真核生物的线粒体-核相互作用的理解。此外，它们与基因组进化、物种形成以及生殖模式变异的功能和进化后果具有广泛的相关性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Intraspecific genetic variation for anesthesia success in a New Zealand freshwater snail

新西兰淡水蜗牛麻醉成功的种内遗传变异

• DOI: 10.1007/s10709-020-00110-6
• 发表时间: 2021
• 期刊: Genetica
• 影响因子: 1.5
• 作者: Song, Qiudong;Magnuson, Richard;Jalinsky, Joseph;Roseman, Marissa;Neiman, Maurine
• 通讯作者: Neiman, Maurine

Parasite resistance predicts fitness better than fecundity in a natural population of the freshwater snail Potamopyrgus antipodarum

在淡水蜗牛 Potamopyrgus antipodarum 的自然种群中，寄生虫抵抗力比繁殖力更能预测健康状况

• DOI: 10.1111/evo.13768
• 发表时间: 2019
• 期刊: Evolution
• 影响因子: 3.3
• 作者: Paczesniak, Dorota;Klappert, Kirsten;Kopp, Kirstin;Neiman, Maurine;Seppälä, Katri;Lively, Curtis M.;Jokela, Jukka
• 通讯作者: Jokela, Jukka