Experimental Population Genetics of Drosophila Mitochondrial DNA

果蝇线粒体 DNA 的实验群体遗传学

• 批准号: 9120293
• 负责人: David Rand
• 金额: $ 60.2万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9120293&HistoricalAwards=false
• 关键词: Experimental; Population; Genetics; Drosophila; Mitochondrial

The general focus of this research is to test the hypothesis that different mitochondrial genomes affect the reproductive rate or "fitness" of the fruit fly Drosophila melanogaster. The research will employ experimental population cages where flies carrying different mitochondrial DNAs (mtDNAs) are competed against one another to determine whether certain mitochondrial genotypes have consistent reproductive advantages over other genotypes. The experiments will involve genetic crosses to construct strains of flies that have the same nuclear chromosomes but differ only in their mtDNAs. Several pairwise tests of competitive ability will be conducted between strains of flies from different populations. The populations have been chosen so that the pairwise tests will involve strains of flies with little, moderate and large amounts of DNA sequence difference between the competing mitochondrial genomes. This should provide a test of the effect of DNA sequence difference on the strength of the fitness different between strains. The research also involves a complementary set of experiments to test the "fitness" of different mtDNAs inside cells. Using a microinjection technique to transplant intact mitochondria between strains of fruit flies, one can create a miniature "population cage" inside the reproductive cells of female flies. By creating reproductive cells with mixtures of different mtDNAs, one can test the hypothesis that different mitochondrial genomes have an advantage in inheritance from mother to offspring. This approach will be employed with the same strains of flies used in the population cage experiments described above. This "two-level" approach to the study of mtDNA variation will provide information on the functional significance of naturally occurring variation in mtDNA and serve as a model system to study the coevolution of nuclear and mitochondrial genomes. Furthermore, this research will test the critical assumption for many studies of population dynamics that mtDNA variation is neutral.

这项研究的总体重点是检验不同线粒体基因组影响果蝇的繁殖率或“健康度”的假设。 该研究将采用实验群体笼，携带不同线粒体 DNA (mtDNA) 的果蝇相互竞争，以确定某些线粒体基因型是否比其他基因型具有一致的繁殖优势。 实验将涉及基因杂交，以构建具有相同核染色体但仅线粒体 DNA 不同的果蝇品系。 将在来自不同种群的果蝇品系之间进行几项成对的竞争能力测试。 群体的选择使得成对测试将涉及竞争线粒体基因组之间具有少量、中等和大量 DNA 序列差异的果蝇品系。 这应该可以测试 DNA 序列差异对菌株间适应性差异强度的影响。 该研究还涉及一组互补的实验来测试细胞内不同线粒体DNA的“适应性”。 使用显微注射技术在果蝇品系之间移植完整的线粒体，可以在雌性果蝇的生殖细胞内创建一个微型“种群笼”。 通过创建具有不同线粒体DNA混合物的生殖细胞，人们可以检验以下假设：不同线粒体基因组在从母亲到后代的遗传中具有优势。 这种方法将用于上述群体笼实验中使用的相同品系的苍蝇。 这种研究线粒体DNA变异的“两级”方法将提供有关线粒体DNA自然发生变异的功能意义的信息，并作为研究核和线粒体基因组协同进化的模型系统。 此外，这项研究将检验许多种群动态研究的关键假设，即线粒体DNA变异是中性的。