Department of Molecular and Cellular Biology and Biochemistry, Brown University, Providence, RI, USA.
Tateyama Marine Laboratory, Marine and Coastal Research Center, Ochanomizu University, Tateyama, Japan.
Proc Biol Sci. 2022 Aug 31;289(1981):20221088. doi: 10.1098/rspb.2022.1088. Epub 2022 Aug 17.
Organisms living on the seafloor are subject to encrustations by a wide variety of animals, plants and microbes. Sea urchins, however, thwart this covering. Despite having a sophisticated immune system, there is no clear molecular mechanism that allows sea urchins to remain free of epibiotic microorganisms. Here, we test the hypothesis that pigmentation biosynthesis in sea urchin spines influences their interactions with microbes using CRISPR/Cas9. We report three primary findings. First, the microbiome of sea urchin spines is species-specific and much of this community is lost in captivity. Second, different colour morphs associate with bacterial communities that are similar in taxonomic composition, diversity and evenness. Lastly, loss of the pigmentation biosynthesis genes polyketide synthase and flavin-dependent monooxygenase induces a shift in which bacterial taxa colonize sea urchin spines. Therefore, our results are consistent with the hypothesis that host pigmentation biosynthesis can, but may not always, influence the microbiome in sea urchin spines.
生活在海底的生物会受到各种动物、植物和微生物的附着。然而，海胆却能阻止这种附着物的生长。尽管海胆拥有复杂的免疫系统，但目前还没有明确的分子机制可以解释为什么海胆能够免受附生微生物的影响。在这里，我们使用 CRISPR/Cas9 技术来检验海胆棘突中的色素生物合成是否会影响它们与微生物的相互作用这一假说。我们报告了三个主要发现。首先，海胆棘突的微生物组是具有物种特异性的，而且其中很大一部分在圈养条件下会丢失。其次，不同颜色的棘突与在分类组成、多样性和均匀度上相似的细菌群落相关联。最后，色素生物合成基因聚酮合酶和黄素依赖型单加氧酶的缺失会诱导细菌分类群在海胆棘突上的定植发生转变。因此，我们的结果与这样一个假说一致，即宿主色素生物合成可以影响海胆棘突中的微生物组，但这种影响可能并不总是存在。
