Karyotype and reproduction mode of the rodent parasite Strongyloides venezuelensis.
Karyotype and reproduction mode of the rodent parasite Strongyloides venezuelensis.
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啮齿动物寄生虫强的核心型核型和繁殖模式。
DOI：
10.1017/s0031182014001036
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发表时间：
2014-11
期刊：
影响因子：
2.4
通讯作者：
Kikuchi T
中科院分区：
文献类型：
--
作者：
Hino A;Tanaka T;Takaishi M;Fujii Y;Palomares-Rius JE;Hasegawa K;Maruyama H;Kikuchi T
松材线虫是一种感染啮齿动物的寄生线虫。虽然迄今为止所描述的线虫在其生活史的寄生阶段表现出孤雌生殖，在自由生活阶段表现出有性繁殖，但我们没有在我们的品系中观察到任何自由生活的雄性线虫，这表明该线虫可能依赖孤雌生殖。我们通过细胞学分析证实，在其生活史的寄生阶段，该虫通过孤雌生殖产生卵子。利用28S核糖体RNA基因18S和D3全序列进行的系统发育分析表明，该菌与另一种啮齿动物寄生虫Strongyloids rati有较远的亲缘关系，而与反刍动物寄生虫Strongyloids Papillosus的亲缘关系较近。染色体组型分析表明，该物种以有丝分裂孤雌生殖方式繁殖，其染色体数目与乳头藻相同(2n=1，4)，但与拉蒂(2，n=1，6)不同。综上所述，这些结果表明，维尼苏尔沙门氏菌对啮齿动物的寄生是独立于拉蒂沙门氏菌的，因此可能有不同的繁殖策略。
Strongyloides venezuelensis is a parasitic nematode that infects rodents. Although Strongyloides species described to date are known to exhibit parthenogenetic reproduction in the parasitic stage of their life cycle and sexual reproduction in the free-living stage, we did not observe any free-living males in S. venezuelensis in our strain, suggesting that the nematode is likely to depend on parthenogenetic reproduction. We confirmed by cytological analysis that S. venezuelensis produces eggs by parthenogenesis during the parasitic stage of its life cycle. Phylogenetic analysis using nearly the full length of 18S and D3 region of 28S ribosomal RNA gene suggested that S. venezuelensis is distantly related to another rodent parasite, namely Strongyloides ratti, but more closely related to a ruminant parasite, Strongyloides papillosus. Karyotype analysis revealed S. venezuelensis reproduces with mitotic parthenogenesis, and has the same number of chromosomes as S. papillosus (2n = 4), but differs from S. ratti (2n = 6) in this regard. These results, taken together, suggest that S. venezuelensis evolved its parasitism for rodents independently from S. ratti and, therefore, is likely to have a different reproductive strategy.