Ecology and Environment Research Centre, Manchester Metropolitan University, Manchester, UK.
School of Environment and Life Sciences, University of Salford, Salford, UK.
J Anim Ecol. 2019 Nov;88(11):1684-1695. doi: 10.1111/1365-2656.13065. Epub 2019 Sep 3.
Marine sponges are hosts to large, diverse communities of microorganisms. These microbiomes are distinct among sponge species and from seawater bacterial communities, indicating a key role of host identity in shaping its resident microbial community. However, the factors governing intraspecific microbiome variability are underexplored and may shed light on the evolutionary and ecological relationships between host and microbiome. Here, we examined the influence of genetic variation and geographic location on the composition of the Ircinia campana microbiome. We developed new microsatellite markers to genotype I. campana from two locations in the Florida Keys, USA, and characterized their microbiomes using V4 16S rRNA amplicon sequencing. We show that microbial community composition and diversity is influenced by host genotype, with more genetically similar sponges hosting more similar microbial communities. We also found that although I. campana was not genetically differentiated between sites, microbiome composition differed by location. Our results demonstrate that both host genetics and geography influence the composition of the sponge microbiome. Host genotypic influence on microbiome composition may be due to stable vertical transmission of the microbial community from parent to offspring, making microbiomes more similar by descent. Alternatively, sponge genotypic variation may reflect variation in functional traits that influence the acquisition of environmental microbes. This study reveals drivers of microbiome variation within and among locations, and shows the importance of intraspecific variability in mediating eco-evolutionary dynamics of host-associated microbiomes.
海洋海绵是大量多样的微生物群落的宿主。这些微生物组在海绵物种之间以及与海水细菌群落之间存在明显差异，表明宿主身份在塑造其常驻微生物群落方面起着关键作用。然而，控制种内微生物组变异性的因素尚未得到充分探索，这可能揭示了宿主和微生物组之间的进化和生态关系。在这里，我们研究了遗传变异和地理位置对 Ircinia campana 微生物组组成的影响。我们开发了新的微卫星标记来对来自美国佛罗里达群岛两个地点的 I. campana 进行基因分型，并使用 V4 16S rRNA 扩增子测序来描述它们的微生物组。我们表明，微生物群落组成和多样性受宿主基因型的影响，遗传上更相似的海绵宿主拥有更相似的微生物群落。我们还发现，尽管 I. campana 在两个地点之间没有遗传分化，但微生物组组成因地点而异。我们的结果表明，宿主遗传学和地理位置都影响海绵微生物组的组成。宿主基因型对微生物组组成的影响可能是由于微生物群落从亲代垂直传递给后代，使得微生物组在遗传上更相似。或者，海绵基因型的变异可能反映了影响环境微生物获取的功能性状的变异。本研究揭示了种内和种间位置微生物组变异的驱动因素，并表明宿主相关微生物组的生态进化动态中种内变异性的重要性。
