DISSERTATION RESEARCH: Origins of Parthenogenesis in the Common Checkered Whiptail

有性生殖的主要优点之一是它能够产生和维持生物多样性，但有些物种是无性繁殖的。这个项目将解决克隆繁殖产生单性蜥蜴遗传多样性的能力，单性蜥蜴是唯一一组能够在没有任何雄性输入的情况下繁殖的脊椎动物。了解单性种群的进化轨迹将有助于确定为什么性是多细胞生命的普遍繁殖模式。该项目的结果和发现将通过以下方式与更广泛的社区建立联系：1）促进培训和指导，2）澄清分类学挑战物种复杂性中的物种水平关系，以及3）通过与墨西哥研究人员的国际合作促进知识专长的交流。利用新兴的基因组方法，独特的蜥蜴模型，和一个国际研究团队的人才，这个项目解决了一个持久的进化问题的进化和维持有性生殖。这个项目的目标是确定的进化过程中，形状生物多样性的克隆繁殖蜥蜴。大多数脊椎动物物种通过有性繁殖来保持遗传变异，但有几种全雌性蜥蜴通过克隆自己来繁殖，而没有雄性;母亲生下的女儿基因组几乎完全相同。然而，克隆是不完美的，因为个体可能由于突变而不能产生基因相同的克隆。为了研究是什么在克隆中产生多样性（包括表型多样性），该项目使用来自一个孤雌生殖的全雌性物种及其相关有性物种的DNA序列来确定是否是多个创始事件或遗传机制最好地解释了表型的多样性。将全基因组基因分型与对整个线粒体基因组进行测序的新方法相结合，这些数据应该可以清楚地了解孤雌生殖物种的起源，并推断有性生殖物种之间的物种水平关系。这项研究将调查的克里思和模式的突变过程中产生的多样性在克隆繁殖的蜥蜴，从而提供洞察的起源和进化的单性在脊椎动物。

One of the primary advantages of sexual reproduction is its ability to generate and maintain biodiversity, yet some species reproduce clonally. This project will address the ability of clonal reproduction to generate genetic diversity in unisexual lizards, the only group of vertebrates capable of reproducing without any input from males. Understanding the evolutionary trajectories of unisexual populations will help identify why sex is the prevalent mode of reproduction for multicellular life. Results and discoveries from this project will connect with the broader community by: 1) promoting training and mentoring, 2) clarifying species level relationships in a taxonomically-challenged species complex, and 3) facilitating exchange of intellectual expertise via international collaborations with Mexican researchers. Using emerging genomic approaches, unique lizard models, and the talents of an international team of researchers, this project addresses a persistent evolutionary question about the evolution and maintenance of sexual reproduction.The goals of this project are to identify the evolutionary processes that shape organismal diversity in a clonally-reproducing lizard. Most vertebrate species maintain genetic variation by reproducing sexually, but several all-female lizards reproduce without males by cloning themselves; mothers beget daughters whose genomes are all but identical. However, cloning is imperfect, as individuals may not produce genetically-identical clones due to mutation. To investigate what generates diversity (including phenotypic diversity) among clones this project uses DNA sequence from one parthenogenetic, all-female species and its related sexual species to determine if either multiple founding events or genetic mechanisms after inception best explain the diversity in phenotypes. Combining genome-wide genotyping with a novel approach to sequence entire mitochondrial genomes, these data should permit a clear picture into the origins of the parthenogenetic species and infer species level relationships among the sexual species. This research will investigate the tempo and mode of mutation processes generating diversity in a clonally-reproducing lizard, thus providing insight into the origins and evolution of unisexuality in vertebrates.