Zarlenga Dante, Thompson Peter, Mitreva Makedonka, Rosa Bruce A, Hoberg Eric
U.S. Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, B1180 BARC-East Beltsville, MD 20705, USA.
Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
Food Waterborne Parasitol. 2022 Apr 18;27:e00155. doi: 10.1016/j.fawpar.2022.e00155. eCollection 2022 Jun.
Evolution involves temporal changes in the characteristics of a species that are subsequently propagated or rejected through natural selection. In the case of parasites, host switching also plays a prominent role in the evolutionary process. These changes are rooted in genetic variation and gene flow where genes may be deleted, mutated (sequence), duplicated, rearranged and/or translocated and then transmitted through vertical gene transfer. However, the introduction of new genes is not driven only by Mendelian inheritance and mutation but also by the introduction of DNA from outside a lineage in the form of horizontal gene transfer between donor and recipient organisms. Once introduced and integrated into the biology of the recipient, vertical inheritance then perpetuates the newly acquired genetic factor, where further functionality may involve co-option of what has become a pre-existing physiological capacity. Upon sequencing the (Clade I) genome, a cyanate hydratase (cyanase) gene was identified that is common among bacteria, fungi, and plants, but rarely observed among other eukaryotes. The sequence of the cyanase gene clusters with those derived from the Kingdom Plantae in contrast to the genes found in some Clade III and IV nematodes that cluster with cyanases of bacterial origin. Phylogenetic analyses suggest that the cyanase was acquired during the Devonian period and independently from those of other nematodes. These data may help inform us of the deep evolutionary history and ecological connectivity of early ancestors within the lineage of contemporary . Further, in many extant organisms, cyanate detoxification has been largely superseded by energy requirements for metabolism. Thus, deciphering the function of cyanase may provide new avenues for treatment and control.
进化涉及一个物种特征随时间的变化，这些变化随后通过自然选择得以传播或被淘汰。就寄生虫而言，宿主转换在进化过程中也起着重要作用。这些变化源于遗传变异和基因流动，基因可能会被删除、突变（序列改变）、复制、重排和/或易位，然后通过垂直基因传递进行传播。然而，新基因的引入不仅由孟德尔遗传和突变驱动，还由供体和受体生物体之间水平基因转移形式的来自谱系外的DNA引入所驱动。一旦引入并整合到受体的生物学特性中，垂直遗传就会使新获得的遗传因子得以延续，其进一步的功能可能涉及对已有的生理能力的利用。在对[某种线虫（进化枝I）]基因组进行测序时，发现了一种氰酸水合酶（氰酶）基因，该基因在细菌、真菌和植物中很常见，但在其他真核生物中很少见。[该线虫的]氰酶基因序列与来自植物界的基因聚类在一起，这与一些进化枝III和IV线虫中发现的与细菌来源的氰酶聚类的基因形成对比。系统发育分析表明，[该线虫的]氰酶是在泥盆纪时期获得的，并且独立于其他线虫的氰酶。这些数据可能有助于我们了解当代[该线虫谱系]早期祖先的深层进化历史和生态联系。此外，在许多现存生物中，氰酸盐解毒在很大程度上已被代谢的能量需求所取代。因此，解读[该线虫的]氰酶功能可能为治疗和控制提供新途径。
