Bowtie: an Ultrafast, Lightweight Short Read Aligner
Bowtie NEWS
===========
Bowtie is now available for download. 0.9.0 is the first version to
be released under the OSI Artistic License (see `COPYING') and freely
available to the public for download. The current version is 0.12.7.
Reporting Issues
================
Please report any issues using the Sourceforge bug tracker:
https://sourceforge.net/tracker/?group_id=236897&atid=1101606
Announcements
=============
To receive announcements (including release announcements) about Bowtie
and related tools (including Crossbow, TopHat, Cufflinks, Myrna)
subscribe to our mailing list:
https://lists.sourceforge.net/lists/listinfo/bowtie-bio-announce
Version Release History
=======================
Version 0.12.7 - September 7, 2010
* Fixes the all-gap reference sequence issue that was present in
Bowtie 0.12.6. Index files produced by bowtie-build 0.12.5 and
earlier (back to 0.10.*) are compatible with bowtie 0.12.7. Index
files produced by bowtie-build 0.12.7 are backward compatible with
bowtie 0.12.5 and earlier as long as the first reference sequence
is not all-gaps (or, when colorspace indexes, as long as the first
reference sequence has two consecutive ACGT characters in it
somewhere).
* Indexes where the first sequence consists of all gaps or other
non-ACGT characters are not handled properly by Bowtie versions
0.12.5 and older, but are handled properly by Bowtie 0.12.7.
* REMOVED: bowtie-build's --old-reverse option; the old reverse-
index scheme is again the default. The new scheme is disabled
pending further refinement.
September 3, 2010
* The version of bowtie-build distributed in Bowtie 0.12.6 IS
BROKEN. It could not handle stretches of ambiguous reference
characters compatibly with prior versions of Bowtie. Please use
Bowtie 0.12.5's bowtie-build instead. Bowtie 0.12.7, due out
soon, will contain a complete set of working tools. Bowtie 0.12.7
will revert to old way of building the reverse index. Sorry for
the inconvenience.
Version 0.12.6 - August 29, 2010
* Modified bowtie-inspect's default mode to use the bit-encoded
reference portion of the index to reconstruct the reference
sequence, rather than the ebwt portion. This makes bowtie-inspect
much faster and uses less memory, and the output for a colorspace
index will now be in nucleotide space. To get the behavior of the
old default, use the new -e/--ebwt-ref option.
* Fixed bug whereby SOLiD QV strings would fail to parse.
* Moved to a new default way of building the reverse index. Revert
to the old behavior with bowtie-build's new --old-reverse option.
The new reverse index format is forward and backward compatible
with `bowtie`, unless otherwise noted in a future version.
* Fixed issue that would sometimes cause bowtie-build to crash when
building a large index with a low --offrate.
* Fixed build issue that would cause bowtie-build built on one
version of Linux to die with a "floating point error" on other
versions.
* Fixed a bug whereby alignment cost could sometimes be
miscalculated. Stratum was unaffected.
* bowtie now simply skips reads with 0 characters. Previously it
would print an error and exit.
Version 0.12.5 - April 10, 2010
* Fixed spurious "Error while writing string output; not all
characters written" errors in -S/--sam mode.
Version 0.12.4 - April 5, 2010
* Periods in read sequences are now treated as Ns instead of
ignored. This should help with some problems where Bowtie
erroneously reports "Reads file contained a pattern with more than
1024 quality values..." for data from recent versions of the
Illumina GA pipeline.
* Fixed a bug whereby some error and warning messages would be
printed on top of each other in -p mode.
* Chunk-exhaustion warnings messages are now suppressed when --quiet
is specified.
* Fixed small issue in quality decoding whereby no-confidence colors
would incorrectly influence decoded quality of adjacent bases.
Version 0.12.3 - February 17, 2010
* Fixed a significant bug in -C/--color mode whereby quality values
for SNP nucleotide positions were erroneously penalized.
* Fixed a bug in -S/--sam mode whereby if whitespace occurred in the
original read name, it would be printed in the QNAME field in
violation of the SAM spec. Bowtie now truncates read names at the
first whitespace character before printing.
* When input is FASTQ and -C/--color is enabled, Bowtie is now
tolerant of output from FASTQ converters that include the primer
base and where the quality string is one character shorter than
the sequence string (due to the primer). This fixes issues users
have reported using output from BFAST's solid2fastq.
* Added support for SOLiD-style _QV files, via the -Q/--quals, --Q1
and --Q2 options. These options are used in combination with
-C/--color and -f to align parallel colorspace read/quality files
without having to convert to FASTQ.
Version 0.12.2 - February 2, 2010
* When -C/--color is enabled, the default paired-end orientation is
now --ff, not --fr. The new default fits typical SOLiD output.
* Fixed a bug whereby very large reads could cause bowtie to crash
in --best mode
* After 0.12.1, some issues remained whereby bowtie would fail to
trim the primer in colorspace (e.g. in -c mode). All input modes
should now have fully-functioning
* Fixed a bug whereby decoded colorspace qualities could overflow
and erroneously become low qualities.
* Fixed a bug that could produce incorrect paired-end alignment
results in -n mode when using paired-end orientation modes other
than --fr. Even with the bug, reported results are reasonable;
but the seed edit constraint (-n) may have been applied to the
wrong end of one of the mates.
* Changed --chunkmbs default up to 64 from 32.
* Better error checking and reporting for some bowtie options.
* Some basic testing scripts are now bundled with Bowtie (in
scripts/test), which should make it easier to regression-test.
Version 0.12.1 - January 8, 2010
* IMPORTANT: Fixed bug whereby bowtie would fail to remove both the
primer base and the first color when parsing .csfasta files with
primer bases in -C -f mode. A workaround for users of version
0.12.0 is to use "-5 1" in that situation.
* Fixed bug whereby, when -M limit was exceeded for an unpaired
read, the number printed in the 7th column for the random
alignment was too low by 1.
* Added documentation discussing a pitfall regarding SOLiD paired-
end input, i.e., not all entries necessarily have corresponding
mates in the other file.
Version 0.12.0 - December 23, 2009
* Added missing README.markdown file
* Minor documentation additions
Version 0.12.0-beta1 - December 12, 2009
* Added SOLiD colorspace support
* Colorspace indexes are distinct from standard letterspace
indexes and must be built with a separate invocation of
bowtie-build (with -C option)
* Running bowtie with -C causes Bowtie to align in colorspace;
both index and reads must be in colorspace
* Colorspace memory requirement is the same as paired-end
alignment in nucleotide-space (normal) mode. Paired-end
alignment does not increase the memory requirement further in
colorspace.
* csfasta, csfastq, and "raw" read formats are all supported with
-C; '0' means "blue" and is intechangeable with 'A', likewise
'1' ('C') means "green", '2' ('G') means "orange" and '3' ('T')
means "red"
* Colorspace versions of pre-built indexes added (see Bowtie web
site)
* New manual section discussing colorspace features
* Fixed a few SAM output issues
* @PG line now properly uses colons instead of equals signs
* Removed /1, /2 suffixes for paired-end reads in SAM mode
* Added --sam-RG option that permits the user to insert set values
for flags that appear on the @RG line
* Fixed lingering pthreads bugs that would cause Bowtie to hang or
crash toward the end of execution with -p > 1.
* Fixed performance-related bug that would cause paired-end
alignment to be artificially slow in many situations.
* Fixed issue with random number generation that would result in
non-random selection of alignments in some situations.
* bowtie -f now supports fasta files with reads split across
multiple lines
* New --suppress option suppresses unwanted columns of output
* The MANUAL file was converted to markdown format, facilitating
conversion to various other formats using tools like pandoc
* DEPRECATED: bowtie: --concise, bowtie-build: --big, --little
* REMOVED: -z/--phased, -b/--binout, bowtie-maptool,
bowtie-maqconvert
Version 0.11.3 - October 12, 2009
* Fixed crashing bug in -S/--sam mode when the number of reference
sequences in the index is very large.
* Added --sam-nohead option to suppress output of SAM headers in
-S/--sam mode.
* Added --sam-nosq option to suppress output of @SQ SAM headers in
-S/--sam mode. These can become a nuisance when the reference
index contains a very large number of sequences.
* Fixed a bug in bowtie-build's auto-configure mode that would cause
it to underestimate the amount of memory required by a set of
parameters. This in turn would cause the index to be corrupted.
Version 0.11.2 - October 7, 2009
* Fixed issue whereby --max option was disabled.
Version 0.11.1 - October 5, 2009
* SAM output: changed XS:i optional field to be named XA:i to avoid
a conflict with TopHat's XS:i field.
Version 0.11.0 - October 5, 2009
* Initial SAM output support with -S/--sam option. Bowtie sets all
fields according to the SAM spec (Version 0.1.2-draft, 20090820).
See the new "SAM Output" section of the manual for details.
* Added --shmem option: --shmem is similar to --mm in that it allows
concurrent 'bowtie' processes querying the same index to share a
single memory image of the index. Unlike --mm, shared memory
alocated by --shmem is permanent.
* The alignment summary printed to stderr at the end of an alignment
run is now more friendly and includes data about the number and
proportion of reads that aligned, failed to align, or were
suppressed via the -m option.
* When too-short reads are encountered, Bowtie now always prints
warnings, not errors. --quiet now suppresses those warnings.
* By default, when bowtie prints a reference sequence name it now
stops at the first whitespace. In 0.10.1, the default was to
print the entire name, which could cause confusion when parsing
Bowtie output. To revert to printing the full name, use the new
--fullref option.
* Bowtie now prints the command-line before exiting with an error.
* Fixed mistake in the manual's "Default output" section: the offset
in field 4 is 0-based, not 1-based. To obtain a 1-based offset
instead, use the -B 1 option.
* Various minor bug fixes.
* DEPRECATED: -z/--phased, -b/--binout, bowtie-maptool,
bowtie-maqconvert. These features will be removed in a future
version of Bowtie. Note that -b/--binout, bowtie-maptool, and
bowtie-maqconvert are largely superseded by the SAM output format
(-S/--sam), BAM, and SAMtools (http://samtools.sf.net). Contact
the authors if this is a problem.
* REMOVED: --unfq/--unfa/--maxfq/--maxfa/--alfq/--alfa. Please use
--un/--max/--al instead. Contact the authors if this is a
problem.
Version 0.10.1 - July 19, 2009
* Now when -3/-5 are used in combination with -I/-X, the -I/-X
constraints are interpreted as applying to the original insert,
not the trimmed insert.
* Fixed issue whereby -I option was ignored; -I option works now.
* Fixed a bug whereby some large indexes were incorrectly reported
as corrupt by bowtie-build.
* Fixed issue whereby negative quality values were wrongly rejected
when both --integer-quals and --solexa-quals were specified.
* The -l/--seedlen parameter can now be adjusted down to 5
(previously had to be >= 20).
* Fixed several minor memory leaks and out-of-bounds issues. The
Linux version of the bowtie aligner now receives a clean bill of
health from valgrind's memcheck.
* Other minor bugfixes.
Version 0.10.0.2 - 6/28/09
* Second bugfix for Windows version. src and bin-win32 packages
updated. Linux and Mac users are not affected. Thanks for your
bug reports and patience.
Version 0.10.0.1 - 6/23/09
* Fix for crashing bug in Windows version. src and bin-win32
packages updated. Linux and Mac users are not affected.
Version 0.10.0 - June 12, 2009
* Major change: All alignment modes are now unstratified by default.
The --nostrata option has been removed, since it is now the
default. A --strata option has been added to override the default
and force stratified reporting. Reporting is stratified if and
only if --strata is specified. --strata now cannot be specified
without also specifying --best. Please note that, because of this
change, specifying the same arguments to this version of Bowtie
may yield different reported results.
* Replaced the --unfa/--unfq options with a single --un option,
which writes unaligned reads to an output file (or pair of output
files) but keeps reads in their original form. This is in
contrast to the old --unfa/--unfq options, which only supported
FASTA or FASTQ formats, and which would print a post-trimming and
post-quality-value translation version of the read. Likewise, the
--alfa/--alfq and --maxfa/--maxfq options have been replaced with
--al and --max options. The old options are still present, but
are deprecated and will be removed in a future version.
* Added --nofw and --norc options, allowing alignment to just one
reference strand or the other.
* Added --mm option that causes bowtie to use memory-mapped files
instead of traditional file I/O to access the reference index.
This allows multiple bowtie processes running on the same computer
to share a single in-memory image of a given index. This is a
useful feature for parallelizing bowtie in situations where memory
is limited and where -p is inappropriate or insufficient. This
feature is not available in the Windows version of Bowtie.
* Added a section to the manual ("Reporting Modes") clarifying and
giving examples of how to use Bowtie's reporting options.
* The --al and -z/--phased options previously interacted in such a
way that the --al file could contain multiple entries for the same
aligned read. --al and -z/--phased are now incompatible.
* The --oldpmap option, deprecated in version 0.9.8, has been
removed.
Version 0.9.9.3 - May 12, 2009
* Fixed an issue where bowtie --best would sometimes use excessive
amounts of memory to store path descriptors. There is now a per-
thread 32-MB ceiling (configurable with new option --chunkmbs
<int>) on the memory taken by path descriptors. If the ceiling is
exceeded Bowtie will skip the offending read, print a warning
message identifying the read, and continue.
* More options are available for defining the quality-value format,
including new --phred64-quals/--solexa1.3-quals options
appropriate for the 64-based-Phred output of Illumina's GA
Pipeline 1.3. Added option --phred33-quals to to handle the more
typical 33-based-Phred scale (the default). The --solexa-quals
option still handles the 64-based-Solexa scale output by GA
Pipeline versions prior to 1.3.
* bowtie-build now checks output files for obvious corruption due,
for example, to disk exhaustion.
* Specifying "-" (meaning stdin) as an input to bowtie is now
supported and documented.
* Fixed a bug whereby bowtie-maqconvert could fail to notice that it
had exhausted memory and output a corrupt Maq map file.
* Fixed a bug whereby bowtie would crash when trying to use an index
built on a machine with different endianness.
* Fixed several issues that prevented Bowtie from compiling on
Solaris. I confirm that Bowtie builds and runs on Solaris.
* Added _LARGEFILE_SOURCE _FILE_OFFSET_BITS=64 _GNU_SOURCE to the
default build options in an attempt to resolve some of the large-
file issues users are having.
* Clarified column 7 in the manual. We received many queries from
users curious about this number.
* Moderate speed improvements in --best mode.
Version 0.9.9.2 - April 6, 2009
* Paired-end alignment is now available in all alignment modes,
including all -n modes.
* --best now provides better guarantees. Reported alignments are
now guaranteed to be "best" both in terms of stratum (i.e. number
of mismatches, or mismatches in the seed in the case of -n mode),
and in terms of the quality values at the mismatched position(s).
Stratum always trumps quality when determining best alignments.
Also, --best mode resolves the strand bias issue (see manual for a
discussion of the issue).
* Speed improvements for --best mode in most alignment modes.
* Major speed improvement for the -v 3 alignment mode (except when
-z is also used)
* The "Reported X alignments..." message is now printed to stderr
rather than stdout. Only alignments are written to stdout.
* In bowtie-maqconvert, read names longer than Maq's limit (36) are
now truncated to a suffix of the original name, rather than a
prefix. This mimics Maq's behavior and prevents "/1" and "/2"
suffixes for paired-end reads from being destroyed.
* Added --alfq/--alfa options to dump aligned reads to FASTQ and/or
FASTA files.
* Removed many extraneous source files.
Version 0.9.9.1 - March 10, 2009
* Added paired-end alignment for -v 2 and -v 3 alignment modes (-n
modes coming soon).
* Minor bug fixes and speed improvements for all paired-end modes.
* Added -s/--skip <int> option to skip over the first <int> reads or
pairs in the input.
* --unfq/--unfa/--maxfq/--maxfa modes no longer create empty output
files.
* All Bowtie tools now compile under GCC 4.3.3.
* Fixed bug whereby bowtie -b would sometimes write garbage into the
reference offset field.
* Paired-end info is now persisted in the -b format, allowing
bowtie-maptool output to add "/1" and "/2" suffixes as
appropriate.
Version 0.9.9 - February 19, 2009
* Added some preliminary support for paired-end alignment in -v 0
and -v 1 modes. -1/-2 options to specify the paired-end files,
-I/-X to specify min and max insert sizes, and --fr/--rf/--ff
specify relative orientation of upstream and downstream mates.
bowtie-build now builds two additional files: NAME.3.ebwt and
NAME.4.ebwt. Together, these files store a bitpacked version of
the reference and they are required for paired-end alignment. If
your index does not include these files and you would like to
perform a paired-end alignment, you will have to rebuild the index
with bowtie-build version 0.9.9 or later. Paired-end alignment is
not compatible with -z mode, and it incurs about a 30% greater
memory overhead than single-end mode.
* Pre-built indexes available from Bowtie website have been updated
to include .3/.4.ebwt index files. These new pre-built indexes
are no longer compatible with bowtie versions prior to 0.9.8.
* New -B/--offbase option allows user to specify how bowtie numbers
reference positions in its output. E.g. -B 1 causes bowtie to
number leftmost char as 1. -B 0 is the default, but -B 1 will
likely become the default in the 1.0 release.
* Fixed a bug that caused trimming options -3 and -5 not to work
properly in -r (raw input) mode.
* bowtie-build now prints a friendly error message and exits if an
input file doesn't exist.
* Fixed a bug that caused the Win32 version of bowtie to hang just
before it would normally have exited.
* Fixed bug that could prevent successful read-in of very large
(>1GB) .2.ebwt index files.
* Removed --maxns option since it's mostly redundant with what -v
and -n already do.
* Removed --ntoa option.
* bowtie usage message is now divided into sections for clarity.
Version 0.9.8.1 - January 7, 2009
* Fixed all known problems with the --unfa/--unfq options:
* They now work properly with multiple threads.
* Fixed issue where sequence and quals were sometimes reversed.
* Fixed other issues causing spurious omission of unaligned reads.
* Added --maxfa/--maxfq options so that reads that don't align due
to the -m limit can be dumped separately from reads that don't
align at all.
* Alignment output is now guaranteed to be "deterministic" even when
multiple threads are used. I.e., given the same input reads (in
any order) and the same --seed, bowtie will produce the same
alignments every time it is run, though not necessarily in the
same order. This does not hold across different versions of
Bowtie.
* Multiple other bug fixes.
Version 0.9.8 - November 25, 2008
* --unfa/--unfq <filename> options cause bowtie to dump unaligned
reads to FASTA and/or FASTQ files.
* bowtie-build now selects its memory-efficiency parameters (--bmax,
--dcv, --packed) automatically by default; this makes it far
easier to build an index under memory constraints by eliminating
tedious trail-and-error. New -a option disables this, yielding
old behavior.
* bowtie-build-packed is no longer a separate binary. Supplying the
new -p/--packed argument to bowtie-build is the new equivalent.
* New tool bowtie-maptool converts between Bowtie's output formats.
* New tool bowtie-inspect recreates reference strings from Bowtie
index.
* Renamed bowtie-convert to bowtie-maqconvert for clarity.
* New universal Mac binary combines i386 & x86_64 binaries. PowerPC
still not supported.
* Added --nomaqround option to bowtie.
* Fixed memory leaks in bowtie.
* Switched to a new scheme for mapping positions in "joined"
reference string to positions in original strings. This changes
the index format. bowtie-build's --oldpmap parameter reverts to
the old format. Versions of bowtie prior to 0.9.8 cannot search
indexes produced by bowtie-build 0.9.8 unless bowtie-build is run
with --oldpmap. bowtie 0.9.8 can search either index format.
Pre-built indexes are still in the old format, but will switch to
new format when Bowtie 1.0 is released.
Version 0.9.7.1 - November 11, 2008
* Fixed an issue that caused a spurious loss of sensitivity between
Bowtie versions 0.9.6 and 0.9.7 in certain modes. Many thanks to
Ali Mortazavi for bringing this to our attention.
Version 0.9.7 - November 8, 2008
* Added new reporting option -m <int> which suppresses all
alignments for a particular read if more than <int> reportable
alignments exist for it.
* Threads now buffer all alignments for a particular read/phase then
output all alignments in one critical section. This guarantees
that all alignments for a given read/phase appear in one
consecutive block of the output, even when multiple threads are
operating in parallel.
* Separated the quality-conversion and parsing aspects of the old
--solexa-quals argument into separate arguments: --solexa-quals
(quality conversion) and --integer-quals (parsing).
* bowtie-convert now handles the new (post-0.7.0) Maq alignment
format. The new format allows Maq tools to handle reads up to
127 bases, whereas the old format was limited to 63 bases. Added
a -o option to opt for the old Maq format.
* New --refout argument sends alignments to a set of files named
refXXXXX.map, where XXXXX is the 0-padded index of the reference
sequence aligned to. Useful for dealing with large datasets
aligned to, e.g., the assembled human genome.
* Improved tutorial to use a simple simulated read set (included)
to do SNP calls with Maq.
* Added --nota option to bowtie-build
* Fixed make_h_sapiens_asm.sh script to include mitochondrial DNA.
Version 0.9.6 - October 10, 2008
* 'bowtie' now supports a host of options that allow the user to
specify which and how many valid alignments to report per read.
The default is still to report 1 "good" alignment, which is by far
the fastest mode. See -k/-a/--best/--nostrata options described
in the manual for details.
* 'bowtie' now supports reads up to 1024 bases long. Note that for
reads much longer than, say, 35 bases, the user must be careful to
set alignment policy parameters (especially -e) appropriately.
* --fast flag eliminated, double-index mode is now the default.
Added the -z/--phased flag to revert to phased, half-index mode.
* --concise output mode now officially supported. Now outputs one
alignment per line.
* Changed 'bowtie-build' default back to --bmaxdivn 4.
* -h/--help now prints much more verbose help for 'bowtie' and
'bowtie-build' (verbatim from MANUAL file)
* BWT-searching code streamlined; much old code eliminated
Version 0.9.5 - September 27, 2008
* Last column of output now additionally reports the reference and
query bases (in that order) for mismatches. E.g., old: "30,32",
new: "30:C>A,32:C>T".
* Eliminated spurious trailing space in first column of output.
* Minor performance and sensitivity improvements.
* New option '-p' spawns a user-specified number of pthreads for
parallel processing of reads. For example, use '-p 4' to run
'bowtie' on 4 processor cores simultaneously.
* Due to the new '-p' option, 'bowtie' needs pthreads to compile and
run. To compile 'bowtie' without pthreads support (which disables
the '-p' option), use 'make BOWTIE_PTHREADS=0'.
* Also due to '-p' option, the Windows version of Bowtie now comes
with the pthreadGC2.dll file from the pthreads for Win32 project
(http://sourceware.org/pthreads-win32). This library is released
under the LGPL license.
* New option '--fast' causes Bowtie to load both the "forward" and
"mirror" halves of the index at once, which eliminates the need
for multiple phases and speeds up matching at the cost of using
about twice as much memory. '--fast' also causes 'bowtie' to
scale better when used in combination with '-p'.
* Fixed crashing bug with -o/--offrate in 'bowtie'.
* Improved error reporting.
Version 0.9.4 - September 16, 2008
* New method for handling gaps and ambiguity codes in the reference.
New 'bowtie-build' method handles long stretches of gaps
gracefully. New 'bowtie' rejects alignments that overlap a gap or
ambiguous character in the reference.
* Due to above change, index file format has been changed. All
pre-built indexes available on this site have been updated to the
new format. To obtain indexes with the old format, contact us.
* In 'bowtie' unnamed reads are now given ordinal names (rather than
"default") in the alignment output. Works for all input modes.
* New 'bowtie' input mode: Raw, activated with -r. Expects one read
sequence per line; no quality values or names.
* Fixed 'bowtie' bug whereby trimming did not work in -c mode.
* Changed 'bowtie-build' default to not use blockwise mode.
* Changed 'bowtie-build' to avoid certain infinite-loop and very-
long-runtime scenarios.
* Packaging improvements: archives now explode into subdirectories
and scripts are executable.
Version 0.9.3 - September 6, 2008
* Major reference-name bug fixes to bowtie-convert
Version 0.9.2 - September 4, 2008
* Now allows 3-mismatches: -n and -v options accept 3
* Output format prints reference name instead of id in third column
* Pre-built indexes updated to encode reference names
* Ns in reads now match nothing (previously, they matched As/Ts)
* Dropped -l/--linerate and -i/--linesperside arguments to bowtie-
build
* Fixed bug in Maq-like mode that allowed some poor alignments
* Minor speed improvements
Version 0.9.1 - August 25, 2008
* Integrated relevant SeqAn-1.1 sources into Bowtie source release
* Now builds on Windows under MinGW (needs pthreads and zlib)
* Binary releases for Linux (i386, x86_64), Windows (i386) and MacOS
X (i386)
Version 0.9.0 - August 18, 2008
* First stable release of Bowtie.
* Includes the three core Bowtie tools: the indexer 'bowtie-build',
the read aligner 'bowtie' and the converter from Bowtie's to Maq's
mapping output format, 'bowtie-convert'.
* Compatible pre-built indexes for many model organisms are
available from http://bowtie-bio.sf.net.
* FASTA, FASTQ inputs supported; tested with Solexa FASTQ
* Supports Maq alignment policy (-n and -e behave as in Maq)
* Supports X-mismatch policy (-v option behaves as in SOAP)
* -n and -v options accept 0, 1, or 2
