Fig. 6: A model describing the microbial ecology and evolution at strain and intrastrain levels in individuals of the sponge C. concentrica holobiont.
From: Decoupling of strain- and intrastrain-level interactions of microbiomes in a sponge holobiont
At the strain level (ANI < 99% MAGs and vOTUs as defined in this study), the community composition of the microbial symbionts and sponge viruses is shaped by the genetic heterogeneity of the sponge hosts. At the intrastrain level (ANI > 99% MAGs and vOTUs down to single cells or viruses), this host impact generally disappears, and microbial cells and viruses are frequently exchanged between sponge hosts. The specificity between viruses and their cellular microbial hosts in sponge holobionts is preserved at the strain to species levels, and interspecific HGTs are generally blocked because of strong immunity. At the intrastrain level, interactions and coevolution between virus-host pairs are frequent resulting in holobiont-specific genetic diversity.
