Methylation Landscape

DNA methylation across Acropora pulchra, Porites evermanni, and Pocillopora tuahiniensis. These are invertebrate-characteristic methylomes.

Coral methylomes are sparse and gene-body-biased. Unlike the canonical vertebrate promoter-silencing model, invertebrate DNA methylation is concentrated in gene bodies (introns & exons), depleted at promoters (5′UTR), and broadly positively associated with expression. Global CpG methylation here is low (4–10%).

Global CpG methylation

Acropora pulchra

9.92%global CpG methylation
WGBS mapping efficiency 50.88%
Sample% mCpG
ACR-140-TP2_S510.21
ACR-145-TP2_S38.72
ACR-150-TP2_S210.42
ACR-173-TP2_S49.39
ACR-178-TP2_S19.84

Porites evermanni

7.24%global CpG methylation
WGBS mapping efficiency 55.72%
Sample% mCpG
POR-71-TP2_S97.20
POR-73-TP2_S77.73
POR-76-TP2_S66.39
POR-79-TP2_S107.40
POR-82-TP2_S87.17

Pocillopora tuahiniensis

4.04%global CpG methylation
WGBS mapping efficiency 57.84%
Sample% mCpG
POC-47-TP2_S133.52
POC-48-TP2_S113.92
POC-50-TP2_S143.62
POC-53-TP2_S153.60
POC-57-TP2_S124.05
Global CpG methylation across species
A. pulchra A. pulchra: 9.92% 9.92% P. evermanni P. evermanni: 7.24% 7.24% P. tuahiniensis P. tuahiniensis: 4.04% 4.04%
Global CpG methylation across species
SeriesValue (%)
A. pulchra9.92
P. evermanni7.24
P. tuahiniensis4.04

Methylation across genomic features

Qualitative feature-level patterns from the manuscript (Figure 1C). Awaiting data A machine-readable per-feature mean-methylation table is not present in the source repository — only a figure. The relative levels below are transcribed from the manuscript text; exact per-feature percentages are pending a numeric summary file.

Genomic featureRelative methylationNotes
Exon moderate–high (gene body) exceeded by intronic methylation in A. pulchra & P. evermanni; higher than intronic in P. tuahiniensis
Intron moderate–high (gene body) < 5% in P. tuahiniensis
5′UTR (promoter) low (depleted) promoter depletion in all species
3′UTR low–moderate
Intergenic low
TE in exon elevated TE CpGs > non-TE CpGs
TE in intron elevated TE CpGs > non-TE CpGs
TE intergenic elevated TE CpGs > non-TE CpGs
miRNA loci predominantly low
lncRNA loci predominantly low

DNA methylation was enriched in gene bodies (introns & exons) and depleted in promoter regions (5′UTR) in all three species, consistent with other invertebrates. CpGs within transposable elements showed higher mean methylation than non-TE CpGs. miRNA and lncRNA loci were predominantly lowly methylated. Per-feature mean methylation values are reported as a figure in the manuscript (Figure 1C); the numeric per-feature summary table is not present as a machine-readable file in the source repository (see data gaps).

Conserved & species-specific methylation (orthogroups)

109methylated in all three species
1,507A. pulchra unique
1,518P. evermanni unique
226P. tuahiniensis unique

510 additional orthogroups are methylated in A. pulchra and P. evermanni but not P. tuahiniensis. The far smaller unique count in P. tuahiniensis (226) reflects its lower global methylation.

Genome browsers

Where genomic coordinates exist, methylation and features can be explored in the source coral genome resources: