PRF/J: Mitochondrial DNA Sequence Variation and the Genetic Structure of Canvasback and Redhead Duck Populations: Direct Sequencing of the Control Region to Improve the Resolution

本研究的主要目的是利用线粒体DNA （mtDNA）控制区的序列变异数据，验证对帆布鸭（Aythya valisineria）和美洲红头鸭（A. americana）种群遗传结构的预测。迁徙的水禽对出生地区的亲缘关系强烈偏向于雌性，而雄性在繁殖之前就广泛分散；这一特点不同于大多数其他鸟类。这种社会系统的独特性表明，尽管核基因的大量流动是由男性分散介导的，但mtDNA的变异可能是地理结构的。换句话说，当地或区域人群的线粒体DNA谱系可能会分化，因为它们与其他母系谱系分离，这是由于女性的位点保真性。这项工作将测试基于性别的哲学对mtDNA基因流的影响是否反映在mtDNA序列变异的地理模式中。mtDNA变异的地理结构将使用来自快速进化控制区的核苷酸序列数据进行评估。这种技术应该允许比限制性内切片段分析更精细的遗传分化分辨率，限制性内切片段分析是几乎所有先前鸟类mtDNA研究中使用的技术。获得关于长途迁徙者遗传结构的细粒度知识，将有助于对北美本土生物多样性的一个重要经济组成部分进行审慎管理。此外，在本研究中获得的见解将推动历史系统地理学（从系统发育的角度来看的地理学），这是生态学和系统学的一个增长点。

The primary objective of this research is to test predictions about the genetic structure of canvasback duck (Aythya valisineria) and redhead duck (A. americana) populations using sequence variation data from the mitochondrial DNA (mtDNA) control region. Philopatry to natal areas is strongly female-biased in migratory waterfowl, whereas males disperse widely prior to the time they breed; this characteristic is unlike that of most other birds. The uniqueness of such a social system suggests that despite a massive flow of nuclear genes mediated by male dispersal, mtDNA variation may be geographically structured. In other words, mitochondrial DNA lineages in local or regional populations may differentiate because they are isolated from other maternal lineages due to female site-fidelity. This work will test whether effects of gender-based philopatry on mtDNA gene flow are reflected in geographic patterns of mtDNA sequence variation. Geographic structure in mtDNA variation is to be evaluated using nucleotide sequence data from the rapidly evolving control region. This technique should permit much finer resolution of genetic differentiation than restriction fragment analysis, the technique used in nearly all previous avian mtDNA investigations. %%% Acquiring fine-grained knowledge about the genetic structure of long-distance migrants will facilitate the prudent management of an economically-important component of native North American biodiversity. In addition insights gained in this research will advance historical phylogeography (geography from a phylogenetic perspective), a growing point in ecology and systematics.