Graduate School of Life Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-Ku, Sendai, 980-8578, Japan.
Microb Ecol. 2023 Oct;86(3):2097-2108. doi: 10.1007/s00248-023-02219-5. Epub 2023 Apr 24.
The taxonomic composition of the microbiota in the gut and epidermis of animals is known to vary among genetically and physiologically different host individuals within the same species. However, it is not clear whether the taxonomic composition diverges with increasing genetic distance of the host individuals. To unveil this uncertainty, we compared the host-associated microbiota among the genotypes within and between genetically distant lineages of parthenogenetic Daphnia cf. pulex across different physiological states, namely, well-fed, starved, and dead. Metagenomic analysis with 16S rRNA showed that, regardless of the host genotypes, diversity of the host-associated microbiota was high when the host individuals were fed food and gradually decreased when they were starved until they died. However, the difference in the host-associated microbiota, that is, β-diversity, was significant among the genotypes within and between the host lineages when they were fed. Although some bacteria in the microbiota, such as Limnohabitans, Rhodococcus, and Aeromicrobium, were found abundantly and commonly in all host genotypes; others, such as those of Holosoporacea, were found only in the genotypes of a specific lineage. Accordingly, the β-diversity tended to increase with increasing genetic distance of the host individuals. These results support an idea that the host-associated microbiota diverged with genetic divergence in the host species and that at least some bacteria are highly dependent on the genetically specific metabolites produced by the host individuals.
动物肠道和表皮微生物群落的分类组成已知会因同一物种内遗传和生理上不同的宿主个体而有所差异。然而，目前尚不清楚分类组成是否会随着宿主个体遗传距离的增加而出现差异。为了揭示这一不确定性，我们比较了不同生理状态下（即饱食、饥饿和死亡），来自同一物种不同遗传距离谱系的孤雌生殖溞属 cf. 卤虫的宿主相关微生物群落。16S rRNA 宏基因组分析表明，无论宿主基因型如何，当宿主个体进食时，其宿主相关微生物群落的多样性都很高，而当它们饥饿时，多样性逐渐降低，直至死亡。然而，当宿主进食时，宿主相关微生物群落之间的差异（即β多样性）在宿主谱系内和之间的基因型之间是显著的。虽然微生物群落中的一些细菌，如 Limnohabitans、Rhodococcus 和 Aeromicrobium，在所有宿主基因型中都大量且普遍存在；而另一些细菌，如 Holosoporacea，则仅存在于特定谱系的基因型中。因此，β多样性随着宿主个体遗传距离的增加而增加。这些结果支持了一个观点，即宿主相关微生物群落随着宿主物种的遗传分化而分化，并且至少有一些细菌高度依赖于宿主个体产生的遗传特异性代谢产物。
