Other Resources

Overview

Teaching: 15 min
Exercises: 0 min
Questions
  • Where can I find other metagenomic resources?

Objectives
  • Know some places where to find more information.

Other resources

We hope that you have found these lessons useful. However, this course is only the start! There is lots more you can learn about analysing and understanding metagenomics, and how to apply these techniques to your own dataset.

A quick roundup of useful learning resources:

There are also some great non-command line resources out there that may be great to get you started. Here are some of our suggestions, although this is by no means an exhaustive list.

MG-RAST

A useful and easy to use resource is MG-RAST, an online metagenomic platform where you can upload your raw data with its corresponding metadata and get a full taxonomic analysis of it. MG-RAST is also a big repository of available data for future experiments.

A downside of this resource is that it is not possible to modify the steps and parameters in the MG-RAST workflow, meaning there is less flexibility for implementing your preferred analysis tools.

Here is an example of some of the figures generated by MG-RAST. It annotates the metabolic function and can give you an idea of what your organisms/ individual MAGs are capable of metabolising.

Pie chart showing the relative abundance at phylum level, and the legend with the phylum names, read count and percentages.

Pie chart showing the relative abundance of general functional categories, and the legend with the category names, read count and percentages.

Pie chart showing the relative abundance of specific functional categories, and the legend with the category names, read count and percentages.

MG-RAST has is a very useful tool for taking a quick look at your data, as well as storing and sharing it.

Krona for visualization

Krona is a hierarchical data visualisation software. It allows data to be explored with zooming, multi-layered pie charts and includes support for several bioinformatics tools and raw data formats. Using Krona you can generate HTML reports on the taxonomy in your metagenome like the one below.

Krona displays a circled-shape bacterial taxonomy plot with abundance percentages of each taxa

iTOL, the interactive tree of life

iTOL is a free website which can be used to generate publication quality phylogenetic trees. Below shows the interface you can use to customise parts of the plot. There are also several video tutorials to show you how to get started. You can also share your trees with other people easily.

This tool is useful if you want to make a tree based on the 16S sequence for several genomes in your metagenome (annotated by Prokka), or if you are interested in a particular set of genes within a genome.

iTOL displays a circular plot with the phylogeny of different bacteria, eukaryotes and archaea, representing the tree of life

KAIJU - alternative classification tool

Kraken2 (the tool we used) is a very popular command line tool for annotating the short reads in your metagenome. KAIJU is another popular tool which has both a command line version and a web based version. It has databases for microbial eukaryotes and viruses as well as bacterial and archaeal refseq genomes.

Here’s what the web version looks like:

iTOL displays a circular plot with the phylogeny of different bacteria, eukaryotes and archaea, representing the tree of life

MetaPhlAn for taxonomic profiling

MetaPhlAn 4 is another very popular tool for profiling taxonomy in microbial communities. The latest associated paper is here.

One benefit of MetaPhlAn is that it has an actively updated github repository as well as an active support forum.It was developed as part of the BioBakery, which also has many other excellent tools and resources.

Identifying functional domains with InterProScan

If you are interested in identifying the functional domain of proteins, InterProScan should be the first tool you use. It has both a command line version for annotating many proteins at once, and a website version for predicting smaller numbers of proteins. It produces an exportable graphical output as shown below.

Screenshot from InterProScan which shows domains that have been identified in a protein sequence

Review articles can be a useful source of information and some contain comprehensive lists of different tools and databases to use for your metagenomic analysis. Here are two we recommend:

Key Points

  • Metagenomes are complicated to analyse. Luckily, there are lots of tools available!

  • The best tools to use change frequently. Do your research when looking for the most suitable tools to use for your analysis.