The Extensive de novo TE Annotator (EDTA)

Table of Contents

• Introduction
• Installation
  • Quick installation using conda
  • Quick installation using Singularity
  • Quick installation using Docker
  • Step by step installation using conda
• Inputs
• Outputs
• EDTA usage
  • From head to toe
  • Divide and conquer
• Benchmarking usage
• Citations
• Other resources
• Issues
• Acknowledgements

Introduction

This package is developed for automated whole-genome de-novo TE annotation and benchmarking the annotation performance of TE libraries.

The EDTA package was designed to filter out false discoveries in raw TE candidates and generate a high-quality non-redundant TE library for whole-genome TE annotations. Selection of initial search programs were based on benckmarkings on the annotation performance using a manually curated TE library in the rice genome.

For benchmarking of a testing TE library, I have provided the curated TE annotation (v6.9.5) for the rice genome (TIGR7/MSU7 version). You may use the lib-test.pl script to compare the annotation performance of your method/library to the methods we have tested (usage shown below).

Installation

There are four ways to install EDTA. Please choose one.

Quick installation using conda (Linux64)

conda install -c bioconda -c conda-forge edta

Quick installation using Singularity (good for HPC users)

Installation:

singularity build --sandbox EDTA.sif docker://kapeel/edta

Usage:

singularity exec {path}/EDTA.sif /EDTA/EDTA.pl --genome genome.fa [other parameters]

{path} is the path you build the EDTA singularity image

Quick installation using Docker (good for root/Mac users)

Installation:

docker pull kapeel/edta

Usage:

docker run -v $PWD:/in -w /in kapeel/edta --genome genome.fa [other parameters]

Step by step installation using conda

conda create -n EDTA
conda activate EDTA
conda config --env --add channels anaconda --add channels conda-forge --add channels bioconda
conda install -n EDTA -y cd-hit repeatmodeler muscle mdust blast openjdk perl perl-text-soundex multiprocess regex tensorflow=1.14.0 keras=2.2.4 scikit-learn=0.19.0 biopython pandas glob2 python=3.6 tesorter genericrepeatfinder genometools-genometools ltr_retriever ltr_finder numpy=1.16.4
git clone https://github.com/oushujun/EDTA
./EDTA/EDTA.pl

Inputs

Required: The genome file [FASTA]. Please make sure sequence names are short (<=15 characters) and simple (i.e, letters, numbers, and underscore).

Optional:

1. Coding sequence of the species or closely related species [FASTA]. This file helps to purge gene sequences in the TE library.
2. Known gene position of this version of the genome assembly [BED]. Coordinates specified in this file will be whitelisted from TE annotation to avoid over-masking.
3. Curated TE library of the species [FASTA]. This file is trusted 100%. Please make sure it's curated. If you only have a couple of curated sequences, that's fine. It doesn't need to be complete.

Outputs

Expected: A non-redundant TE library: $genome.mod.EDTA.TElib.fa. The curated library is included in this file if provided. TEs are classified into the superfamily level and using the three-letter naming system reported in Wicker et al. (2007). Each sequence can be considered as a TE family.

Optional:

1. Novel TE families: $genome.mod.EDTA.TElib.novel.fa. This file contains TE sequences that are not included in the curated library (--curatedlib required).
2. Whole-genome TE annotation: $genome.mod.EDTA.TEanno.gff. This file contains both structurally intact and fragmented TE annotations (--anno 1 required).
3. Summary of whole-genome TE annotation: $genome.mod.EDTA.TEanno.sum (--anno 1 required).
4. Low-threshold TE masking: $genome.mod.MAKER.masked. This is a genome file with only long TEs (>=1 kb) being masked. You may use this for de novo gene annotations. Annotated gene models should contain TEs and need further filtering (--anno 1 required).
5. Annotation inconsistency for simple TEs; $genome.mod.EDTA.TE.fa.stat.redun.sum (--evaluate 1 required).
6. Annotation inconsistency for nested TEs: $genome.mod.EDTA.TE.fa.stat.nested.sum (--evaluate 1 required).
7. Oveall annotation inconsistency: $genome.mod.EDTA.TE.fa.stat.all.sum (--evaluate 1 required).

EDTA Usage

From head to toe

You got a genome and you want to get a high-quality TE annotation:

perl EDTA.pl [options]
  --genome	[File]	The genome FASTA
  --species [Rice|Maize|others]	Specify the species for identification of TIR candidates. Default: others
  --step	[all|filter|final|anno] Specify which steps you want to run EDTA.
			all: run the entire pipeline (default)
			filter: start from raw TEs to the end.
			final: start from filtered TEs to finalizing the run.
			anno: perform whole-genome annotation/analysis after TE library construction.
  --overwrite	[0|1]	If previous results are found, decide to overwrite (1, rerun) or not (0, default).
  --cds	[File]	Provide a FASTA file containing the coding sequence (no introns, UTRs, nor TEs) of this genome or its close relative.
  --curatedlib	[file]	Provided a curated library to keep consistant naming and classification for known TEs.
			All TEs in this file will be trusted 100%, so please ONLY provide MANUALLY CURATED ones here.
			This option is not mandatory. It's totally OK if no file is provided (default).
  --sensitive	[0|1]	Use RepeatModeler to identify remaining TEs (1) or not (0, default).
			This step is very slow and MAY help to recover some TEs.
  --anno	[0|1]	Perform (1) or not perform (0, default) whole-genome TE annotation after TE library construction.
  --rmout	[File]	Provide your own homology-based TE annotation instead of using the EDTA library for masking. File is in RepeatMasker .out format. This file will be merged with the structural-based TE annotation. (--anno 1 required). Default: use the EDTA library for annotation.
  --evaluate	[0|1]	Evaluate (1) classification consistency of the TE annotation. (--anno 1 required). Default: 0.
			This step is slow and does not affect the annotation result.
  --exclude	[File]	Exclude bed format regions from TE annotation. Default: undef. (--anno 1 required).
  --threads|-t	[int]	Number of theads to run this script (default: 4)
  --help|-h	Display this help info

Divide and conquer

Identify intact elements of a paticular TE type:

1.Get raw TEs from a genome (specify -type ltr|tir|helitron in different runs)

perl EDTA_raw.pl [options]
  --genome	[File]	The genome FASTA
  --species [Rice|Maize|others]	Specify the species for identification of TIR candidates. Default: others
  --type	[ltr|tir|helitron|all]	Specify which type of raw TE candidates you want to get. Default: all
  --overwrite	[0|1]	If previous results are found, decide to overwrite (1, rerun) or not (0, default).
  --threads|-t	[int]	Number of theads to run this script
  --help|-h	Display this help info

2.Finish the rest of the EDTA analysis (specify -overwrite 0 and it will automatically pick up existing results in the work folder)

perl EDTA.pl --overwrite 0 [options]

Benchmarking

If you developed a new TE method/got a TE library and want to compare it's annotation performance to the methods we have tested, you can:

1.annotate the rice genome with your test library:

RepeatMasker -e ncbi -pa 36 -q -no_is -norna -nolow -div 40 -lib custom.TE.lib.fasta -cutoff 225 rice_genome.fasta

2.Test the annotation performance of a particular TE category.

perl lib-test.pl -genome genome.fasta -std genome.stdlib.RM.out -tst genome.testlib.RM.out -cat [options]
    -genome	[file]	FASTA format genome sequence
    -std	[file]	RepeatMasker .out file of the standard library
    -tst	[file]	RepeatMasker .out file of the test library
    -cat	[string]	Testing TE category. Use one of LTR|nonLTR|LINE|SINE|TIR|MITE|Helitron|Total|Classified
    -N	[0|1]	Include Ns in total length of the genome. Defaule: 0 (not include Ns).
    -unknown	[0|1]	Include unknown annotations to the testing category. This should be used when
                    the test library has no classification and you assume they all belong to the
                    target category specified by -cat. Default: 0 (not include unknowns)

eg.

perl lib-test.pl -genome rice_genome.fasta -std ./EDTA/database/Rice_MSU7.fasta.std6.9.5.out -tst rice_genome.fasta.test.out -cat LTR

Citations

Please cite our paper if you find EDTA is useful:

Ou S., Su W., Liao Y., Chougule K., Agda J. R. A., Hellinga A. J., Lugo C. S. B., Elliott T. A., Ware D., Peterson T., Jiang N.✉, Hirsch C. N.✉ and Hufford M. B.✉ (2019). Benchmarking Transposable Element Annotation Methods for Creation of a Streamlined, Comprehensive Pipeline. Genome Biol. 20(1): 275.

Please also cite the software packages that were used in EDTA, listed in the EDTA/bin directory.

Other resources

You may download the rice genome here.

Issues

If you have any issues with installation and usage, please check if similar issues have been reported in Issues or open a new issue. If you are (looking for) happy users, please read or write successful cases here.

Acknowledgements

I want to thank Jacques Dainat for contribution of the EDTA conda recipe as well as improving the codes. I also want to thank Qiushi Li, Zhigui Bao, Philipp Bayer, Nick Carleson, @aderzelle, Shanzhen Liu, Zhougeng Xu, Shun Wang, Nancy Manchanda, and many more others for testing, debugging, and improving the EDTA pipeline.