Testing the Utility of Mitochondrial Genome Rearrangements as Phylogenetic Markers in Ischnocera (Insecta:Phthiraptera)

利用基因组数据分析构建系统发育树的方法对结论的解释具有重要意义。因此，新的分析方法在被接受之前需要经过测试。卡梅隆博士和他的同事们的目标是，利用基因排列中的变异（倒置、调换、缺失或重复），测试一系列拟议的方法，从从最大的虱子亚目——Ischnocera的许多物种收集的基因组数据中推断出进化模式。测试系统是这些虱子的线粒体基因组。线粒体是细胞中产生能量的部分，它们的基因组比主要的核基因组小数千倍，这使得对大量物种进行测序成为可能，从而允许进行全面的比较。虱子是研究线粒体基因组进化的模型系统，因为它们具有最快的基因组进化速度和最多的基因重排。这种进化速度使得从少数物种中提取大量信息成为可能，并将这些信息与通过其他手段（虱子解剖和基因序列）推断出的进化模式进行比较。卡梅伦和他的同事将收集的关于虱子线粒体基因组的数据集将为分析方法的比较提供经验数据。这项研究将支持一名年轻的博士后研究员在杨百翰大学怀廷教授的实验室工作，研究新兴的比较基因组学领域。研究的主题涉及基本的生物学问题，如物种如何进化，它们如何彼此分化，以及它们如何发展新的基因。这反过来又应用于医学研究，以了解疾病的遗传基础，特别是那些受线粒体基因组突变影响的疾病。通过研究比核基因组更小、更简单的基因组，卡梅伦博士和他的同事们试图扩展比较基因组学发展的分析基础。

The methods by which genomic data are analyzed to construct phylogenetic trees are of vital significance in interpreting conclusions. Consequently, new methods of analysis need to be tested before they can be accepted. Dr. Cameron and his colleagues aim to test a range of proposed methods to infer evolutionary patterns from genomic data collected from numerous species of the largest suborder of lice, the Ischnocera, using variations (inversions, transpositions, losses or duplications) in the arrangement of genes. The test system is the mitochondrial genome of these lice. Mitochondria are the energy-producing portion of the cell, and their genomes are thousands of times smaller than the main nuclear genome, making it possible to sequence a large number of species and hence allowing comprehensive comparisons. Lice (Insecta: Phthiraptera) are a model system for studying mitochondrial genome evolution because they havethe fastest documented rate of genomic evolution with the largest numbers of gene rearrangements. This evolutionary speed makes it possible to draw a large amount of information out of a small number of species and to compare this information with evolutionary patterns deduced by other means (louse anatomy and gene sequences). The dataset which Cameron and colleagues will collect on louse mitochondrial genomes will provide empirical data on which analytical methods can be compared. This study will support a young postdoctoral investigator working in the laboratory of Prof. Whiting at Brigham Young University, in the emerging field of comparative genomics. Topics under study relate to basic biological questions such as how species evolve, how they diverge from one another, and how they develop new genes. This in turn has applications in medical research towards understanding the genetic basis of disease, particularly those affected by mutations in the mitochondrial genome. By studying genomes smaller and simpler than the nuclear genome, Dr. Cameron and his colleagues seek to extend the analytical foundations from which comparative genomics can grow.