Extreme resistance of bdelloid rotifers to ionizing radiation
Extreme resistance of bdelloid rotifers to ionizing radiation
复制标题
DOI：
10.1073/pnas.0800966105
复制
发表时间：
2008-04-01
影响因子：
11.1
通讯作者：
Meselson, Matthew
中科院分区：
文献类型：
--
作者：
Gladyshev, Eugene;Meselson, Matthew
蛭形轮虫是一种常见的无脊椎动物，具有极不寻常的特征，包括明显的专性无性生殖，在任何生命阶段干燥后恢复繁殖的能力，以及缺乏不易于水平传播的转座遗传因子。我们发现蛭形轮虫对电离辐射（IR）也有很强的抵抗力。繁殖的蛭形虫Adineta vaga和Philodina roseola是更耐IR比Euchlanis rectuata，轮虫属于干燥不耐受性和facultimesexual类Monogononta，和所有其他动物，我们已经找到了相关的数据。类比的干燥和耐辐射的细菌耐辐射异常球菌，我们建议蛭形轮虫的非凡的耐辐射性是其进化适应生存情节的干燥在其特有的栖息地遇到的后果，并在这些事件中发生的损害包括DNA断裂，修复后再水化。这种断裂和修复可能维持了蛭形轮虫染色体的共线对，并保持了低的转座遗传元件的负载，也可能有助于蛭形轮虫成功避免了大多数无性繁殖体所遭受的早期灭绝。
Rotifers of class Bdelloidea are common invertebrate animals with highly unusual characteristics, including apparently obligate asexuality, the ability to resume reproduction after desiccation at any life stage, and a paucity of transposable genetic elements of types not prone to horizontal transmission. We find that bdelloids are also extraordinarily resistant to ionizing radiation (IR). Reproduction of the bdelloids Adineta vaga and Philodina roseola is much more resistant to IR than that of Euchlanis dilatata, a rotifer belonging to the desiccation-intolerant and facultatively sexual class Monogononta, and all other animals for which we have found relevant data. By analogy with the desiccation- and radiation-resistant bacterium Deinococcus radiodurans, we suggest that the extraordinary radiation resistance of bdelloid rotifers is a consequence of their evolutionary adaptation to survive episodes of desiccation encountered in their characteristic habitats and that the damage incurred in such episodes includes DNA breakage that is repaired upon rehydration. Such breakage and repair may have maintained bdelloid chromosomes as colinear pairs and kept the load of transposable genetic elements low and may also have contributed to the success of bdelloid rotifers in avoiding the early extinction suffered by most asexuals.