Data_for_manuscript_submission.zip from Adoption of alternative life cycles in a parasitic trematode is linked to microbiome differences

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 remained 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而言，生活史的兼性截断是其应对传播逆境的适应性策略。然而，为何部分同种个体能够缩短自身生活史，而其余同种个体却无法实现这一过程，目前该问题仍未得到充分阐释。本研究针对同种吸虫（trematodes）展开实验，旨在比较两类个体的微生物组（microbiome）组成差异：一类遵循正常三宿主生活史，另一类则在中间宿主体内通过幼体生殖（progenesis）提前繁殖，从而跳过终末宿主。通过对16S SSU rRNA基因V4高变区进行测序以表征细菌群落，结果显示：无论宿主身份与时间波动如何，正常发育与幼体生殖的吸虫个体体内均存在相同的细菌类群。但本研究记录的所有细菌门以及三分之二的细菌科，在两种形态型个体中的丰度均存在差异：部分类群在正常发育个体中丰度更高，其余类群则在幼体生殖个体中丰度更高。尽管本研究的证据仅为相关性结果，但我们的发现揭示了微生物组差异与生活史路径的种内可塑性之间存在微弱关联。未来可借助功能基因组学与微生物组实验操控技术，对本研究发现的生物学意义开展进一步验证。