Hello Puli, I was trying to create the hints file from the transcripts from the ref. These were steps that i followed blat -minIdentity=92 genome.fa cdna.fa cdna.psl blat2hints.pl --in=cdna.psl --out=hints.E.gff augustus --species=human --hintsfile=hints.E.gff --extrinsicCfgFile=extrinsic.ME.cfg genome.fa
Maker pipeline i have not worked on that much. i would thankful if you provide some information on that.
Thank you
Hi,
First, Are you trying to predict genes in ab-initio, meaning you are trying to predict genes for the first time? Have you tried to run Augustus?
In augustus command line,
you need to select a species name in species directory of augustus. The species must be a close species to your species. Later, you will get a gene prediction results. Pick some scaffolds and their .gff file and have a look at Artemis tool to check whether augustus predicted genes correctly (check exon and intron boundaries) and number of genes of your species. And also compare gene number with species that are close to your species.
Later, run augustus training step. at the step you will generate gene prediction parameters for your own species. Using new parameters, run new gene prediction. In the new prediction, use your own gene parameters and check results in Artemis. Keep doing training step until you get best gene prediction results (gene sets).
and let me know you need help.
Hello Mehmet, Thank you for your reply, I have used augustus many times for other genomes like rice, honeybee. I have question over here. Q 1. Which close species should be considered for running augustus( my sample is goat). Q 2 . Training step do i have to use the output from first step or wt is exct way. Thank you for your kind help.
Hi mks002,
Q 1. Which close species should be considered for running augustus( my sample is goat).
A1: You can have a look species list of augustus, and compare them to find which is closely related to goat species. For instance, have a look a paper that shows phylogenetic relationships of goat species with other species and check which one or ones are listed in species list of augustus.
Q 2 . Training step do i have to use the output from first step or wt is exct way. A2: After finding closely species to goat species, you need to use its parameters in augustus. Then, you will get a gene prediction results. Using the results, you need to start training step. In the training step, you need to use a new parameter (for instance, goat1.). Then, start a new gene prediction using goat1 as a species in species argument in augustus. After finishing new gene prediction with goat1 parameter, have a look results on Artemis. Repeat training step until you get best gene models. In each new gene prediction, use new species parameter. For instance, goat2, goat3, goat4, ...so on. According to my personal experience, you need to do at least 10 training step. Consider that goat genome should be more complex.
Please write if something is not clear or you need additional help. I can guide you.
Thank you for the detailed response.
1 . I went through some papers and then checked the closest species in augustus, human is what is only closest i observed.
2 . Say i predicted the genes first time using humans with human parameters (on default) it will do gene prediction. Using this result what new parameters should be considered (for instance goat 1). Basically what should be going in for training as input files and with what format. Also what would be the training commands.
OK. Just let me know when you finish the first gene prediction using human as species parameters. Later, I will guide you step by step.
Hello, Completed the gene prediction with the closest reference. Predicted ~40 k gene , which is close to one of the genes in one of the goat reference genome. should i go with steps. Thanks in advance
Hi,
Good. First you need to check gene features of your species with the reference species. For this,
Use eval.2.8.8 tool. Please download and install it. In the eval tool, there is a script get_general_stats.pl. This script uses .gtf files as input. You need to convert gff file produced by augustus. For this, use gffread command in cufflinks suite. For example, gffread yourfile.gff -T -o yourfile.gtf. Later, use yourfile.gtf and referencegoat.gtf in get_general_stats.pl script. Compare results. Later, we will start training step. Please let me know when you finish.
Hello , Thank you for your extended help. The results have been compared and observed stats as below
Description -------------1st column (sample goat)----------2nd column (ref goat)
Gene All stats
Transcript all stats
Exon All stats
Command i used get_general_stats.pl -q -A Sample_file.gtf ref_file.gtf
Hi Can you modify these results? I can not see very well. Please show parameters below:
number of genes number of proteins average exon number average intron number median exon median intron exon per gene etc.
Please reformat these results.
first gene prediction looks good based on the stats. Now you need to check other features. For this;
Please install Artemis tool from http://www.sanger.ac.uk/science/tools/artemis
Later, load genome.fa and bam file (from Tophat) to Artemis with gff file.
Please 1) Check intron-exon boundaries to see RNA reads should not cover intron, should cover only exons. 2) Check start and stop codons on genes.
have a look this tutorial:
https://img.jgi.doe.gov/docs/docs/genome-qa.pdf
You should notice that gene prediction is a time consuming process. You need to get best gene models to move to next step of your work.
Let me know when you finish. We need to perform manual gene curation and using curated genes we will start augustus training step.
For Artemis which bam file to upload since no alignment was performed. For this assembly Rna-seq data is not available. So we can go ahead ? what would be feasible solution.
This might give less reliable results if you do not have RNA-seq data. RNA-seq data is necessary to confirm gene predictions. Alternatively, you can check gene predictions using blast. For this, open fasta and gff file in artemis. Then, click on each gene and run blast to look at possible matches.
Try to run gene prediction using other gene prediction tools. Later, use EVM tool (https://evidencemodeler.github.io)
Now since Augustus gene models are already there can we go ahead with training steps.
Since Genome size ~3 gb it is quite time taking to go through all the processes. Can we do one step of training the augustus and work on it.
Artemis loading this big genome also is great trouble (error in loading automatically closing down). If it is just for validation and visualization can work ahead. Regards
You can select the first and second scaffolds of your genome and load them to Artemis. The first and second scaffolds are the biggest ones in your genome. My concerns are to make sure about your gene sets, as your downstream analyses absolutely depend on good gene sets.This is why I want you to get best gene sets.Lack of RNA-seq data is a big problem in producing reliable gene sets, because you will need to perform gene prediction based on hints files (using exon, intron, and intron+exon parameters).
For augustus training; you need about 700 curated genes, of which 500 genes for training and 200 genes test (have a look (ftp://188.44.46.157/New/augustus.2.7/docs/tutorial/training.html) and (http://avrilomics.blogspot.com.tr/2013/04/training-augustus-gene-finding-software.html) What you need to do are: 1. Pick the first and second scaffolds and load them to artemis separately with their corresponding gff file. 2. Check each gene using blast to confirm good matches in blast database, and delete genes that do not have good matches or have zero matches. 3. Keeps only genes that have good matches in blast searches. 4. Save each scaffold as genbank format (.gb) in artemis.
and let me know if you need.
I have >100Mb some 10 scaffolds. And picking one one gene would not be feasible i think need to rework some other way.