Throughout their life cycle, Babesia parasites alternate between a mammalian host, where they cause babesiosis, and the tick vector. Transition between hosts results in distinct environmental signals that influence patterns of gene expression, consistent with the morphological and functional changes operating in the parasites during their life stages. In addition, comparing differential patterns of gene expression among mammalian and tick parasite stages can provide clues for developing improved methods of control. Hereby, we upgraded the genome assembly of Babesia bovis, a bovine hemoparasite, closing a 139 kbp gap, and used RNA-Seq datasets derived from mammalian blood and tick kinete stages to update the genome annotation. Of the originally annotated genes, 1,254 required structural changes, and 326 new genes were identified, leading to a different predicted proteome compared to the original annotation. Next, the RNA-Seq data was used to identify B. bovis genes that were differentially expressed in the vertebrate and arthropod hosts. In blood stages, 28% of the genes were upregulated up to 300 fold, whereas 26% of the genes in kinetes, a tick stage, were upregulated up to >19,000 fold. We thus discovered differentially expressed genes that may play key biological roles and serve as suitable targets for the development of vaccines to control bovine babesiosis.

在它们的整个生命周期中，巴贝虫寄生虫在哺乳动物宿主和蜱媒之间交替出现，在那里它们会引起巴贝虫病。宿主之间的转换会产生影响基因表达模式的不同环境信号，这与寄生虫在其生命阶段的形态和功能变化一致。此外，比较哺乳动物和蜱寄生虫阶段之间基因表达的差异模式可以为开发改进的控制方法提供线索。在此，我们升级了牛巴贝斯虫的基因组组装，一种牛血寄生虫，关闭了 139 kbp 的差距，并使用源自哺乳动物血液和蜱动体阶段的 RNA-Seq 数据集来更新基因组注释。在最初注释的基因中，有 1,254 个需要结构变化，并且鉴定了 326 个新基因，导致与原始注释相比预测的蛋白质组不同。接下来，RNA-Seq 数据用于鉴定在脊椎动物和节肢动物宿主中差异表达的牛双歧杆菌基因。在血液阶段，28% 的基因上调高达 300 倍，而在蜱虫阶段，26% 的基因上调高达 >19,000 倍。因此，我们发现了差异表达的基因，这些基因可能起着关键的生物学作用，并可作为开发控制牛巴贝斯虫病疫苗的合适靶点。