1 #summary Tutorial for multiple sequence alignments and phylogenetic methods in BioRuby -- under development!
9 Tutorial for multiple sequence alignments and phylogenetic methods in [http://bioruby.open-bio.org/ BioRuby].
11 Eventually, this is expected to be placed on the official !BioRuby page.
13 Author: [http://www.cmzmasek.net/ Christian M Zmasek], Sanford-Burnham Medical Research Institute
16 Copyright (C) 2011 Christian M Zmasek. All rights reserved.
19 = Multiple Sequence Alignment =
22 == Multiple Sequence Alignment Input and Output ==
24 === Reading in a Multiple Sequence Alignment from a File ===
26 The following example shows how to read in a *ClustalW*-formatted multiple sequence alignment.
32 # Reads in a ClustalW-formatted multiple sequence alignment
33 # from a file named "infile_clustalw.aln" and stores it in 'report'.
34 report = Bio::ClustalW::Report.new(File.read('infile_clustalw.aln'))
36 # Accesses the actual alignment.
37 msa = report.alignment
39 # Goes through all sequences in 'msa' and prints the
40 # actual molecular sequence.
48 === Writing a Multiple Sequence Alignment to a File ===
51 The following example shows how to write a multiple sequence alignment in *FASTA*-format. It first creates a file named "outfile.fasta" for writing ('w') and then writes the multiple sequence alignment referred to by variable 'msa' to it in FASTA-format (':fasta').
57 # Creates a new file named "outfile.fasta" and writes
58 # multiple sequence alignment 'msa' to it in fasta format.
59 File.open('outfile.fasta', 'w') do |f|
60 f.write(msa.output(:fasta))
64 ==== Setting the Output Format ====
66 The following symbols determine the output format:
68 * `:clustal` for ClustalW
70 * `:phylip` for PHYLIP interleaved (will truncate sequence names to no more than 10 characters)
71 * `:phylipnon` for PHYLIP non-interleaved (will truncate sequence names to no more than 10 characters)
73 * `:molphy` for Molphy
76 For example, the following writes in PHYLIP's non-interleaved format:
79 f.write(align.output(:phylipnon))
83 === Formatting of Individual Sequences ===
87 !BioRuby can format molecular sequences in a variety of formats.
88 Individual sequences can be formatted to (e.g.) Genbank format as shown in the following examples.
92 seq.to_seq.output(:genbank)
95 For Bio::!FlatFile entries:
97 entry.to_biosequence.output(:genbank)
100 The following symbols determine the output format:
101 *`:genbank` for Genbank
106 == Calculating Multiple Sequence Alignments ==
108 !BioRuby can be used to execute a variety of multiple sequence alignment
109 programs (such as [http://mafft.cbrc.jp/alignment/software/ MAFFT], [http://probcons.stanford.edu/ Probcons], [http://www.clustal.org/ ClustalW], [http://www.drive5.com/muscle/ Muscle], and [http://www.tcoffee.org/Projects_home_page/t_coffee_home_page.html T-Coffee]).
110 In the following, examples for using the MAFFT and Muscle are shown.
115 The following example uses the MAFFT program to align four sequences
116 and then prints the result to the screen.
117 Please note that if the path to the MAFFT executable is properly set `mafft=Bio::MAFFT.new(options)` can be used instead of explicitly indicating the path as in the example.
123 # 'seqs' is either an array of sequences or a multiple sequence
124 # alignment. In general this is read in from a file as described in ?.
125 # For the purpose of this tutorial, it is generated in code.
126 seqs = ['MFQIPEFEPSEQEDSSSAER',
127 'MGTPKQPSLAPAHALGLRKS',
132 # Calculates the alignment using the MAFFT program on the local
133 # machine with options '--maxiterate 1000 --localpair'
134 # and stores the result in 'report'.
135 options = ['--maxiterate', '1000', '--localpair']
136 mafft = Bio::MAFFT.new('path/to/mafft', options)
137 report = mafft.query_align(seqs)
139 # Accesses the actual alignment.
140 align = report.alignment
142 # Prints each sequence to the console.
143 align.each { |s| puts s.to_s }
149 * Katoh, Toh (2008) "Recent developments in the MAFFT multiple sequence alignment program" Briefings in Bioinformatics 9:286-298
151 * Katoh, Toh 2010 (2010) "Parallelization of the MAFFT multiple sequence alignment program" Bioinformatics 26:1899-1900
161 # 'seqs' is either an array of sequences or a multiple sequence
162 # alignment. In general this is read in from a file as described in ?.
163 # For the purpose of this tutorial, it is generated in code.
164 seqs = ['MFQIPEFEPSEQEDSSSAER',
165 'MGTPKQPSLAPAHALGLRKS',
169 # Calculates the alignment using the Muscle program on the local
170 # machine with options '-quiet -maxiters 64'
171 # and stores the result in 'report'.
172 options = ['-quiet', '-maxiters', '64']
173 muscle = Bio::Muscle.new('path/to/muscle', options)
174 report = muscle.query_align(seqs)
176 # Accesses the actual alignment.
177 align = report.alignment
179 # Prints each sequence to the console.
180 align.each { |s| puts s.to_s }
186 * Edgar, R.C. (2004) "MUSCLE: multiple sequence alignment with high accuracy and high throughput" Nucleic Acids Res 32(5):1792-1797
188 === Other Programs ===
190 _need more detail here..._
192 [http://probcons.stanford.edu/ Probcons], [http://www.clustal.org/ ClustalW], and [http://www.tcoffee.org/Projects_home_page/t_coffee_home_page.html T-Coffee] can be used in the same manner as the programs above.
196 == Manipulating Multiple Sequence Alignments ==
198 Oftentimes, multiple sequence to be used for phylogenetic inference are 'cleaned up' in some manner. For instance, some researchers prefer to delete columns with more than 50% gaps. The following code is an example of how to do that in !BioRuby.
212 = Phylogenetic Trees =
215 == Phylogenetic Tree Input and Output ==
218 === Reading in of Phylogenetic Trees ===
222 ====Newick or New Hampshire Format====
232 ====phyloXML Format====
234 Partially copied from [https://www.nescent.org/wg_phyloinformatics/BioRuby_PhyloXML_HowTo_documentation Diana Jaunzeikare's documentation].
236 In addition to !BioRuby, a libxml Ruby binding is also required. This can be installed with the following command:
239 % gem install -r libxml-ruby
242 This example reads file "example.xml" and stores its [http://www.phyloxml.org/ phyloXML]-formatted trees in variable 'trees'.
248 # This creates new phyloXML parser.
249 trees = Bio::PhyloXML::Parser.new('example.xml')
251 # This prints the names of all trees in the file.
256 # If there are several trees in the file, you can access the one you wish via index.
272 === Writing of Phylogenetic Trees ===
274 ====Newick or New Hampshire Format====
284 ====phyloXML Format====
286 Partially copied from [https://www.nescent.org/wg_phyloinformatics/BioRuby_PhyloXML_HowTo_documentation Diana Jaunzeikare's documentation].
288 In addition to !BioRuby, a libxml Ruby binding is also required. This can be installed with the following command:
291 % gem install -r libxml-ruby
294 This example writes trees 'tree1' and 'tree2' to file "tree.xml" in [http://www.phyloxml.org/ phyloXML] format.
300 # this creates new phyloXML writer.
301 writer = Bio::PhyloXML::Writer.new('tree.xml')
303 # Writes tree to the file "tree.xml".
306 # Adds another tree to the file.
324 = Phylogenetic Inference =
326 _Currently !BioRuby does not contain wrappers for phylogenetic inference programs, thus I am progress of writing a RAxML wrapper followed by a wrapper for FastME..._
328 == Optimality Criteria Based on Character Data ==
330 Character data based methods work directly on molecular sequences and thus do not require the calculation of pairwise distances but tend to be time consuming and sensitive to errors in the multiple sequence alignment.
332 === Maximum Likelihood ===
355 === Maximum Parsimony ===
357 Currently no direct support in !BioRuby.
360 === Bayesian Inference ===
362 Currently no direct support in !BioRuby.
365 == Pairwise Distance Based Methods ==
367 === Pairwise Sequence Distance Estimation ===
378 === Optimality Criteria Based on Pairwise Distances ===
381 ==== Minimal Evolution: FastME ====
391 === Algorithmic Methods Based on Pairwise Distances ===
393 ==== Neighbor Joining and Related Methods ====
409 == Support Calculation? ==
411 === Bootstrap Resampling? ===
416 = Analyzing Phylogenetic Trees =
421 == Gene Duplication Inference ==
423 _need to further test and then import GSoC 'SDI' work..._
431 = Putting It All Together =
433 Example of a small "pipeline"-type program running a mininal phyogenetic analysis: starting with a set of sequences and ending with a phylogenetic tree.