Fig 1.
The bacterial microbiome of Aurelia AcGM is dominated by two taxa.
(A) To characterize the jellyfish-associated microbiome associated with Aurelia ACGM, we performed next-generation amplicon sequencing of the V4 region of the 16S rRNA gene. Each biological replicate comes from 3–5 animals. The top ten taxa, color-coded, are listed in Fig 1B. (B) The top ten most abundant taxa present in Aurelia AcGM across life stages. Percent abundance shown is the average across biological replicates. The last column shows average (‘Ave’) across life stages. In the last row, the ratios of Mollicutes and Rickettsiales abundance are computed across life stages.
Fig 2.
Microbiome composition of Aurelia varies across geographical populations.
(A) Geographic locations of Aurelia populations that have been analyzed so far for their microbiome composition. (B) Bacterial families found to associate with Aurelia studied so far. Families included in this pie chart make up at least 5% of the relative abundance. We plotted the family level because this is the lowest common taxonomic classification reported in all of the studies. The numbers in parentheses indicate the number of geographical locations in which the families were found to associate with an Aurelia species. The colors simply group the families based on the number of geographical occurrences. See S4 Table in S10 File for the detailed survey of the existing Aurelia microbiome studies.
Table 1.
Aurelia from several parts of the world associate with a Mollicutes likely of the same species.
We surveyed existing studies that characterize bacteria that associate with Aurelia for Mollicutes association. S4 Table in S10 File provides the detailed taxa composition recovered from each study.
Fig 3.
Metagenome-assembled genomes (MAGs) of the Aurelia AcGM-associated Mollicutes and Rickettsiales.
The MAGs were recovered from the host genomic sequencing reads [24]. (A) Circos plots of Aurelia Mollicutes and Aurelia Rickettsiales MAGs. (B) Assembly statistics for the Aurelia Mollicutes and Aurelia Rickettsiales MAGs. More detailed statistics are described in S5 Table in S10 File. (C-E) Representative genomes of bacterial species were retrieved from the NCBI RefSeq database. Genome size and number of protein coding sequences were plotted for Mollicutes (C), Rickettsiales (D) and representative genomes of all accepted bacterial species (E). Genome size and number of protein coding sequences are log10 transformed for visualization.
Fig 4.
Bacteria that associate with Aurelia AcGM are likely new species.
A concatenated maximum-likelihood phylogenetic tree was constructed using IQ-TREE with ultra-fast bootstrapping (n = 2000). Ultrafast bootstrap support values are shown for each branch point. The number of species comprising collapsed branches are shown in parentheses. (A) Phylogenetic reconstruction of the Aurelia Mollicutes. Eleven single-copy orthologs from 128 Mollicutes species were analyzed. (B) Phylogenetic reconstruction of the Aurelia Rickettsiales. Fifty-six single-copy orthologs from 82 Rickettsiales species were analyzed.