Wilson Isabella, Perry Tahlia, Eisenhofer Raphael, Rismiller Peggy, Shaw Michelle, Grutzner Frank
School of Biological Sciences, The University of Adelaide, Adelaide 5005, Australia.
Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, The University of Adelaide, Adelaide 5005, Australia.
FEMS Microbiol Ecol. 2025 Apr 14;101(5). doi: 10.1093/femsec/fiaf036.
Monotreme and marsupial development is characterized by a short gestation, with young exposed to the environment at an early developmental stage and supported by a long lactation in the pouch, pseudo-pouch, or burrow. The lack of a functional adaptive immune system in these altricial young raises questions about how they survive in a microbe-rich environment. Previous studies on marsupial pouches have revealed changes to pouch microbe composition during lactation, but no information is available in monotremes. We investigated changes in the echidna pseudo-pouch microbiota (n = 22) during different stages of the reproductive cycle and whether this differs between wild and zoo-managed animals. Metataxonomic profiling using 16S rRNA gene sequencing revealed that pseudo-pouch microbial communities undergo dramatic changes during lactation, with significant differences in taxonomic composition compared with samples taken outside of breeding season or during courtship and mating. This suggests that the echidna pseudo-pouch environment changes during lactation to accommodate young that lack a functional adaptive immune system. Furthermore, captivity was not found to have a significant effect on pseudo-pouch microbiota. This study pioneers pouch microbiota research in monotremes, provides new biological information on echidna reproduction, and may also provide information about the effects of captive management to inform breeding programmes in the future.
单孔目动物和有袋动物的发育特点是妊娠期短，幼崽在发育早期就暴露于外界环境中，并在育儿袋、假育儿袋或洞穴中通过长时间的哺乳得到养育。这些发育不全的幼崽缺乏功能性的适应性免疫系统，这引发了关于它们如何在微生物丰富的环境中生存的问题。先前对有袋动物育儿袋的研究揭示了哺乳期间育儿袋微生物组成的变化，但关于单孔目动物的此类信息尚无报道。我们调查了针鼹假育儿袋微生物群（n = 22）在生殖周期不同阶段的变化，以及野生和圈养管理的动物之间是否存在差异。使用16S rRNA基因测序进行宏分类分析表明，假育儿袋微生物群落在哺乳期间会发生显著变化，与繁殖季节之外或求偶及交配期间采集的样本相比，分类组成存在显著差异。这表明针鼹假育儿袋环境在哺乳期间会发生变化，以容纳缺乏功能性适应性免疫系统的幼崽。此外，未发现圈养对假育儿袋微生物群有显著影响。本研究开创了单孔目动物育儿袋微生物群的研究，提供了关于针鼹繁殖的新生物学信息，也可能提供有关圈养管理影响的信息，为未来的繁殖计划提供参考。
