Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Otago Micro and Nano Imaging, Electron Microscopy Unit, University of Otago, Dunedin 9016, New Zealand.
Biol Lett. 2023 Jun;19(6):20230091. doi: 10.1098/rsbl.2023.0091. Epub 2023 Jun 7.
For parasites with complex multi-host life cycles, the facultative truncation of the cycle represents an adaptation to challenging conditions for transmission. However, why certain individuals are capable of abbreviating their life cycle while other conspecifics are not remains poorly understood. Here, we test whether conspecific trematodes that either follow the normal three-host life cycle or skip their final host by reproducing precociously (via progenesis) in an intermediate host differ in the composition of their microbiomes. Characterization of bacterial communities based on sequencing of the V4 hypervariable region of the 16S SSU rRNA gene revealed that the same bacterial taxa occur in both normal and progenetic individuals, independent of host identity and temporal variation. However, all bacterial phyla recorded in our study, and two-thirds of bacterial families, differed in abundance between the two morphs, with some achieving higher abundance in the normal morph and others in the progenetic morph. Although the evidence is purely correlative, our results reveal a weak association between microbiome differences and intraspecific plasticity in life cycle pathways. Advances in functional genomics and experimental microbiome manipulation will allow future tests of the significance of these findings.
对于具有复杂多宿主生活史的寄生虫来说，周期的兼性截断代表了对传播挑战性条件的适应。然而，为什么某些个体能够缩短其生命周期，而其他同物种个体却不能，这仍然知之甚少。在这里，我们测试了是否遵循正常的三宿主生活史或通过在中间宿主中过早繁殖（通过幼态发生）跳过其最终宿主的同种吸虫在其微生物组的组成上存在差异。基于 16S SSU rRNA 基因 V4 高变区测序对细菌群落进行的特征描述表明，相同的细菌分类群出现在正常和幼态发生个体中，与宿主身份和时间变化无关。然而，我们研究中记录的所有细菌门和三分之二的细菌科在两种形态之间的丰度存在差异，其中一些在正常形态中丰度更高，而另一些在幼态发生形态中丰度更高。尽管证据纯粹是相关的，但我们的结果揭示了微生物组差异与生命周期途径的种内可塑性之间的弱关联。功能基因组学和实验微生物组操作的进步将允许未来对这些发现的意义进行测试。
