Abstract：
Platyhelminthes, also known as flatworms, is a phylum of bilaterian invertebrates infamous for their parasitic representatives. The classes Cestoda, Monogenea, and Trematoda comprise parasitic helminths inhabiting multiple hosts, including fishes, humans, and livestock, and are responsible for considerable economic damage and burden on human health. As in other animals, the genomes of flatworms have a wide variety of paralogs, genes related via duplication, whose origins could be mapped throughout the evolution of the phylum. Through in-silico analysis, we studied inparalogs, i.e., species-specific duplications, focusing on their biological functions, expression changes, and evolutionary rate. These genes are thought to be key players in the adaptation process of species to each particular niche. Our results showed that genes related with specific functional terms, such as response to stress, transferase activity, oxidoreductase activity, and peptidases, are overrepresented among inparalogs. This trend is conserved among species from different classes, including free-living species. Available expression data from Schistosoma mansoni, a parasite from the trematode class, demonstrated high conservation of expression patterns between inparalogs, but with notable exceptions, which also display evidence of rapid evolution. We discuss how natural selection may operate to maintain these genes and the particular duplication models that fit better to the observations. Our work supports the critical role of gene duplication in the evolution of flatworms, representing the first study of inparalogs evolution at the genome-wide level in this group.
摘要：
桔梗，也被称为扁虫，是一个因其寄生代表而臭名昭著的双边无脊椎动物门。Cestoda班，Monogenea,而雷马塔包括寄生蠕虫，居住在多个寄主中，包括鱼类,人类,牲畜,并对人类健康造成巨大的经济损失和负担。和其他动物一样，扁虫的基因组有各种各样的旁系同源物，通过复制相关的基因，其起源可以在整个门的进化过程中绘制。通过硅分析，我们研究了inparalogs，即，特定物种的重复，专注于它们的生物学功能，表达式更改,和进化率。这些基因被认为是物种适应每个特定生态位的关键参与者。我们的结果表明，与特定功能术语相关的基因，比如对压力的反应，转移酶活性，氧化还原酶活性，和肽酶，在inparalogs中代表过多。这种趋势在不同类别的物种之间是保守的，包括自由生活的物种。来自曼氏血吸虫的可用表达数据，吸虫类的寄生虫,表现出内在同源物之间表达模式的高度保守性，但除了值得注意的例外，这也显示了快速进化的证据。我们讨论了自然选择如何操作以维持这些基因以及更适合观察的特定复制模型。我们的工作支持基因复制在扁虫进化中的关键作用，代表了该组中在全基因组水平上对同源物进化的首次研究。
