Detwiler Jillian T, Zajac Anne M, Minchella Dennis J, Belden Lisa K
Department of Biology, Texas A&M University, College Station, Texas 77843, USA.
J Parasitol. 2012 Dec;98(6):1148-55. doi: 10.1645/GE-3117.1. Epub 2012 Jun 13.
Many trematode groups have a long history of systematic revision, which can make parasite identification a difficult task. The trematode parasites of muskrats are no exception. Here, we highlight the systematic issues associated with trematodes of muskrats (Ondatra zibethicus). Then, we demonstrate the utility of using both morphological and molecular tools to identify these parasites. Morphological examinations of specimens from muskrats (n = 63) first suggested that at least 4 genera were present including Echinostoma, Wardius, Quinqueserialis, and Notocotylus. For the latter 3 groups, the 28S region verified this assessment. For echinostomes, ND1 sequences revealed at least 5 genetic lineages. A particular lineage, Echinostoma trivolvis lineage b, predominated in both prevalence and intensity of infection. Molecular sequences provided a more accurate estimate of echinostome diversity in the muskrats and further support the idea that E. trivolvis is a species complex. Future studies will focus on whether there are differences in host specificity among the E. trivolvis lineages. In addition, this study has provided initial sequences that will help verify the life cycles of Wardius, Quinqueserialis, and especially, Notocotylus. By linking molecular, morphological, and life history information, we can better understand parasite diversity.
许多吸虫类群有着长期的系统修订历史，这可能使寄生虫鉴定成为一项艰巨的任务。麝鼠的吸虫寄生虫也不例外。在这里，我们强调与麝鼠（麝鼠属）吸虫相关的系统问题。然后，我们展示了使用形态学和分子工具来鉴定这些寄生虫的实用性。对来自麝鼠的标本（n = 63）进行形态学检查首先表明至少存在4个属，包括棘口吸虫属、沃德吸虫属、五口吸虫属和背孔吸虫属。对于后3个类群，28S区域证实了这一评估。对于棘口吸虫，ND1序列揭示了至少5个遗传谱系。一个特定的谱系，即三歧棘口吸虫谱系b，在感染率和感染强度上均占主导地位。分子序列提供了对麝鼠中棘口吸虫多样性更准确的估计，并进一步支持了三歧棘口吸虫是一个复合物种的观点。未来的研究将集中在三歧棘口吸虫谱系之间宿主特异性是否存在差异。此外，本研究提供了初步序列，这将有助于验证沃德吸虫属、五口吸虫属，特别是背孔吸虫属的生命周期。通过将分子、形态学和生活史信息联系起来，我们可以更好地理解寄生虫的多样性。
