The comparative method is a powerful approach in genomics research. Based on our knowledge about the phylogenetic relationships between species, we can study the evolution, diversification, and constraints of biological processes by comparing genomes, genes, and other genomic loci across species. The
orthologr package aims to provide a framework to perform large scale comparative genomics studies with R.
Orthologr aims to be as easy to use as possible - from genomic data retrieval to orthology inference and dNdS estimation between several genomes.
In combination with the R package biomartr, users can retrieve genomes, proteomes, or coding sequences for several species and use them as input for orthology inference and dN/dS estimation with
orthologr. The advantage of using
biomartr in combination with
orthologr is that users can join the new wave of research that promotes and facilitates computational reproducibility in genomics studies and solve the issue of comparing genomes with different genome assembly qualities (also referred to as genome version crisis).
You can find a detailed list of all
orthologr functions here: https://drostlab.github.io/orthologr/reference/index.html
Please cite the following paper in which I introduce
orthologr when using this package for your own research. This will allow me to continue working on this software tool and will motivate me to extend its functionality and usability in the next years. Many thanks in advance :)
Drost et al. 2015. Evidence for Active Maintenance of Phylotranscriptomic Hourglass Patterns in Animal and Plant Embryogenesis. Mol. Biol. Evol. 32 (5): 1221-1231. doi:10.1093/molbev/msv012
orthologr allows users to perform orthology inference and dN/dS estimation between two genomes or between several genomes. The following methods to infer orthologous relationships between genes of entire genomes are available in this package:
The most useful implementation in
orthologr is the ability to compute synonymous versus non-synonymous substitution rates (dN/dS) for all orthologous genes between two entire genomes. Available dN/dS estimation methods are:
Please find more details here.
# Install Bioconductor if (!requireNamespace("BiocManager", quietly = TRUE)) install.packages("BiocManager") BiocManager::install() # Install package dependencies BiocManager::install(c( "Biostrings", "GenomicRanges", "GenomicFeatures", "Rsamtools", "rtracklayer" )) # install metablastr from GitHub devtools::install_github("drostlab/metablastr") # install orthologr from GitHub devtools::install_github("drostlab/orthologr")
orthologr by reading these tutorials:
library(orthologr) # Detect orthologous genes between a query species and a subject species # and compute the synonymous versus non-synonymous substitution rates (dN/dS) # following this paradigm: # 1) reciprocal best hit for orthology inference (RBH) # 2) Needleman-Wunsch for pairwise amino acid alignments # 3) pal2nal for codon alignments # 4) Comeron for dNdS estimation # 5) multi-core processing 'comp_cores = 1' dNdS(query_file = system.file('seqs/ortho_thal_cds.fasta', package = 'orthologr'), subject_file = system.file('seqs/ortho_lyra_cds.fasta', package = 'orthologr'), delete_corrupt_cds = TRUE, # coding sequences that cannot be divided by 3 (triplets) will be removed ortho_detection = "RBH", # perform BLAST best reciprocal hit orthology inference aa_aln_type = "pairwise", # perform pairwise global alignments of AA seqs aa_aln_tool = "NW", # using Needleman-Wunsch codon_aln_tool = "pal2nal", # perform codon alignments using the tool Pal2Nal dnds_est.method = "Comeron", # use Comeron's method for dN/dS inference comp_cores = 1 )
# A tibble: 20 x 24 query_id subject_id dN dS dNdS perc_identity num_ident_match… alig_length <chr> <chr> <dbl> <dbl> <dbl> <dbl> <int> <int> 1 AT1G010… 333554|PA… 0.106 0.254 0.420 74.0 347 469 2 AT1G010… 470181|PA… 0.0402 0.104 0.388 91.1 224 246 3 AT1G010… 470180|PA… 0.0150 0.126 0.118 95.5 343 359 4 AT1G010… 333551|PA… 0.0135 0.116 0.116 92.0 1812 1970 5 AT1G010… 909874|PA… 0 0.175 0 100 213 213 6 AT1G010… 470177|PA… 0.0449 0.113 0.397 89.5 580 648 7 AT1G010… 918864|PA… 0.0183 0.106 0.173 95.1 348 366 8 AT1G010… 909871|PA… 0.0340 0.106 0.322 90.3 271 300 9 AT1G010… 470171|PA… 0.00910 0.218 0.0417 96.8 420 434 10 AT1G011… 333544|PA… 0.0325 0.122 0.266 93.6 494 528 11 AT1G011… 918858|PA… 0.00307 0.133 0.0232 99.2 525 529 12 AT1G011… 470161|PA… 0.00567 0.131 0.0432 98.5 446 453 13 AT1G011… 918855|PA… 0.13 0.203 0.641 72.6 207 285 14 AT1G011… 918854|PA… 0.105 0.280 0.373 84.9 152 179 15 AT1G011… 311317|PA… 0 0.306 0 85.6 83 97 16 AT1G011… 909860|PA… 0.0297 0.176 0.168 92.6 287 310 17 AT1G011… 311315|PA… 0.0287 0.162 0.177 94.2 502 533 18 AT1G012… 470156|PA… 0.0190 0.168 0.114 95.8 228 238 19 AT1G012… 311313|PA… 0.0207 0.154 0.134 95.3 102 107 20 AT1G012… 470155|PA… 0.0157 0.153 0.102 96.7 1021 1056 # … with 16 more variables: mismatches <int>, gap_openings <int>, n_gaps <int>, # pos_match <int>, ppos <dbl>, q_start <int>, q_end <int>, q_len <int>, qcov <int>, # qcovhsp <int>, s_start <int>, s_end <dbl>, s_len <dbl>, evalue <dbl>, bit_score <dbl>, # score_raw <dbl>
When running your own query file, please specify
query_file = "path/to/your/cds.fasta instead of
system.file(..., package = "orthologr"). The command
system.file(..., package = "orthologr") merely references the path to the example file stored in the
orthologr package itself.
install.packages("biomartr") library(biomartr) # download all coding sequences for Mus musculus Mmusculus_file <- biomartr::getCDS(organism = "Mus musculus", path = getwd()) # download all coding sequences for Homo sapiens Hsapiens_file <- biomartr::getCDS(organism = "Homo sapiens", path = getwd()) # compute dN/dS values for Homo sapiens versus Mus musculus Hs_vs_Mm_dNdS <- dNdS(query_file = Hsapiens_file, subject_file = Mmusculus_file, delete_corrupt_cds = FALSE, ortho_detection = "RBH", aa_aln_type = "pairwise", aa_aln_tool = "NW", codon_aln_tool = "pal2nal", dnds_est.method = "Comeron", comp_cores = 1 ) # store result in Excel readable csv file install.packages("readr") readr::write_excel_csv(Hs_vs_Mm_dNdS, "Hs_vs_Mm_dNdS.csv")
Users can find the corresponding map at https://github.com/drostlab/dNdS_database.
This way, users can compute dN/dS values for any pairwise genome comparison.
In some cases (when working with WINDOWS machines), the installation via
devtools will not work properly. In this case users can try the follwing steps:
# On Windows, this won't work - see ?build_github_devtools install_github("drostlab/orthologr", build_vignettes = TRUE, dependencies = TRUE) # When working with Windows, first users need to install the # R package: rtools -> install.packages("rtools") # Afterwards users can install devtools -> install.packages("devtools") # and then they can run: devtools::install_github("drostlab/orthologr", build_vignettes = TRUE, dependencies = TRUE) # and then call it from the library library("orthologr", lib.loc = "C:/Program Files/R/R-3.1.1/library")
orthologron a Win 8 laptop: solution ( Thanks to Andres Romanowski )
orthologs(): Main Orthology Inference Function
I would be very happy to learn more about potential improvements of the concepts and functions provided in this package.
Furthermore, in case you find some bugs, need additional (more flexible) functionality of parts of this package, or want to contribute to this project please let me know:
orthologr package includes source code that has been published under following licenses:
All files included in `orthologr` that were taken from gestimator are also part of libsequence. libsequence is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. libsequence is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License long with libsequence. If not, see <http://www.gnu.org/licenses/>. Modified by Sarah Scharfenberg and Hajk-Georg Drost (2014) to work in orthologr without using external libraries from libsequence. All changes are also free under the terms of GNU General Public License version 2 of the License, or any later version.