- In this worksheet you will learn how to calculate the average nucleotide identity between a set of genomes using fastANI as implemented in Galaxy
Required prerequisite(s)
- You must create an account on https://usegalaxy.eu/ and log in to that account
Suggested prerequisite(s)
- An understanding of how to use Galaxy. Some good guidance: https://www.youtube.com/watch?v=uVNdyrVDYYU
- An understanding of how fastANI works: https://www.nature.com/articles/s41467-018-07641-9
Dataset
- This demonstration uses the fasta files of a set of closely related bacterial whole genome sequences
- Download this dataset and unzip it to a folder on your computer.
Steps
- In your web browser, navigate to https://usegalaxy.eu/
- Log in to your account using the ‘Login or Register’ button in the top navigation bar
- We want to upload all the genome fasta files together into a single collection so we can process them together.
- Click ‘Upload Data’ on the left of the screen and then select ‘Collection’ at the top.
- Drag and drop all 6 fasta files from the dataset into the box and when finished press ‘Start’
- Once upload is finished, click ‘Build’
- Enter a name for your collection in the ‘Name:’ box and then click ‘Create collection’
- It can take a few minutes for your collection to be built but you should see it appear in green in the right hand history section.
- In the lefthand side menu, in the search box under ‘Tools’ type FastANI
- Click on ‘fastANI fast alignment-free computation of whole-genome Average Nucleotide Identity’
- The fastANI tool will now appear in the centre of the screen. This tool will compare 1 or more query genomes to a set of one or more reference genomes
- You can have the same set of genomes as both query and reference to perform an all-vs-all comparison
- Under ‘Query Sequences’ click the icon that looks like a folder to the left of the input box to input a collection
- Click the collection you made in step 6.
- Repeat this for the ‘Reference Sequences’ box
- There are no additional options to set for fastANI so click ‘Run Tool’
- An output will appear in your history starting with ‘FastANI on…’. When this turns green your results are ready.
- Click the eye icon on the FastANI output entry in your history on the righthand side.
- The pairwise ANI of each set of two genomes is listed here
- Try to find the genome(s) which doesnt seem to be in the same species as the other (i.e. <95% ANI)