Green Crab Experiment Part 20
Making a plan for metabolomics analysis
Analytical workflow
Before I jumped into analysis, I surveyed some recent metabolomics papers to see if I could come up with a consensus on analytical method:
- PLS-DA in
mixOmics
package - WCNA with WGCNA correlated to identify with coral developmental time points
- analyzed for enrichment of compound class and KEGG pathway with MetaboAnalyst web interface
- DGCA for correlation of metabolite pairs between ambient and stressed Mcap
- Significant correlations —> used to create co-occurrence networks
- PCA then PLS-DA
- VIP identified from PLS-DA
- ANOVA for differences in metabolites between groups
- functional enrichment and pathway topology analysis (takes into account role of metabolite, position, and direction of interaction in a network)
- MetaboAnalyst used for all analyses
- All analyses in R except for PLS-DA and random forest analyses in MetaboAnalyst
- Remove compounds detected in less than half of crabs prior to downstream analyses
- univariate analyses: two-way ANOVA for each compound (OA + DO), Benjamini-Hochberg FDR correction. sig compounds (model ANOVA < 0.01 and effect < 0.05 w/o FDR correction) used for pathway analyses
- multivariate: normalized by mean-centering and scaling, PLS-DA with default settings
- Metamapp: map metabolite relationships
Looks like a PLS-DA and some sort of MetaboAnalyst enrichment are common place, so I’ll start there! Huffmyer et al. (2023) has the most recent scripts available on Github, so I’ll base a lot of my work off of that.
Going forward
- Analyze metabolomics data
Written on November 10, 2023