A genome informatics approach to discover the genetic determinants of the evolution of parasitism in nematode worms.

线虫种类广泛，是动植物的重要寄生虫。这种寄生已经从自由生活的祖先物种独立进化了多次。支持寄生的生物学机制被编码在线虫的基因组中。我的研究计划的长期目标是了解基因组的哪些区域进化了，以及这是如何导致我们在今天的寄生线虫中观察到的行为和生化特征的起源和维持的。使用基因组学，生物信息学和进化生物学方法的组合，我的研究计划检查基因复制的进化和基因家族的生长在家畜的自由生活和寄生线虫的基因组。大的基因家族与生物体对环境的反应有关。这些基因家族的变化通常与对新环境的适应有关，这可能导致新物种的出现。超过20种感兴趣的线虫物种——隐杆线虫（自由生活）和圆线虫（家畜寄生虫）——的全基因组测序使我们能够测试物种进化中的各种关键问题。我们将确定不同的基因家族是否在自由生活和寄生物种中迅速进化。我们将确定那些在独立适应牛寄生的物种中平行进化的基因家族。还将确定使密切相关的Haemonchus物种适应不同宿主寄生的遗传决定因素。最后，我们将利用基因表达和蛋白质结构数据来预测这些重要基因家族中蛋白质功能的变化。总的来说，这些研究目标旨在显著提高我们对基因组如何响应新环境而进化的理解，以及这些变化如何支持在新环境中的适应和固定。这对很多物种都有影响，而不仅仅是寄生虫。

Species of nematodes are ubiquitous, and significant parasites of animals and plants. This parasitism has evolved multiple times independently from free-living ancestral species. The biological mechanisms that support parasitism are encoded in the nematodes' genomes. The long-term objectives of my research program are to understand which regions of the genome evolved, and how this leads to the origin and maintenance of the behaviour and biochemical traits that we observe in today's parasitic nematodes. Using a combination of genomics, bioinformatics and evolutionary biology approaches, my research program examines the evolution of gene duplications and growth of gene families in the genomes of both free-living and parasitic nematodes of livestock animals. Large gene families are implicated in responding to an organism's response to its environment. Changes in these gene families frequently correlate to the adaptation of a new environment, which can lead to the emergence of a new species. The fully sequenced genomes of over 20 nematode species of interest - Caenorhabditis (free-living) and Strongylida (livestock parasites) - enable us to test various key questions in species evolution. We will determine whether different gene families are evolving rapidly in free-living and parasitic species. We will identify those gene families that are evolving in parallel in species that have independently adapted to the parasitism of cattle. The genetic determinants that enable closely related species of Haemonchus to adapt to parasitism of different hosts will also be identified. Finally, we will use gene expression and protein structural data to predict how protein function changes in these important gene families. Overall, these research objectives aim to significantly improve our understanding of how the genome evolves in response to new environments and how these changes support the adaptation and fixation in that new environment. This has implications across a broad range of species, not only parasites.