Bio::SeqIO::game::featHandler - a class for handling feature elements
Index
Code Index:
NAME
Bio::SeqIO::game::featHandler -- a class for handling feature elements
SYNOPSIS
This module is not used directly
DESCRIPTION
Bio::SeqIO::game::featHandler converts game XML <annotation>
elements into flattened Bio::SeqFeature::Generic objects to be added
to the sequence
FEEDBACK
Mailing Lists
User feedback is an integral part of the evolution of this
and other Bioperl modules. Send your comments and suggestions preferably
to one of the Bioperl mailing lists.
Your participation is much appreciated.
bioperl-l@bioperl.org - General discussion
http://bioperl.org/wiki/Mailing_lists - About the mailing lists
Support
Please direct usage questions or support issues to the mailing list:
bioperl-l@bioperl.org
rather than to the module maintainer directly. Many experienced and
reponsive experts will be able look at the problem and quickly
address it. Please include a thorough description of the problem
with code and data examples if at all possible.
Reporting Bugs
Report bugs to the Bioperl bug tracking system to help us keep track
of the bugs and their resolution. Bug reports can be submitted via the
web:
https://redmine.open-bio.org/projects/bioperl/
AUTHOR - Sheldon McKay
APPENDIX
The rest of the documentation details each of the object
methods. Internal methods are usually preceded with a _
new
Title : new
Usage : my $featHandler = Bio::SeqIO::game::featHandler->new($seq, $seq_h, $ann_l)
Function: creates an object to deal with sequence features
Returns : a handler object
Args : $seq -- a Bio::SeqI compliant object
$seq_h -- ref. to a hash of other sequences associated
with the main sequence (proteins, etc)
$ann_l -- ref. to a list of annotations
add_source
Title : add_source
Usage : $featHandler->add_source($seq->length, \%tags);
Function: creates a source feature
Returns : a Bio::SeqFeature::Generic object
Args : sequence length and a ref. to a hash of tag/value attributes
has_gene
Title : has_gene
Usage : my $gene = $self->_has_gene($gene, $gname, $id)
Function: method to get/set the current gene feature
Returns : a Bio::SeqFeature::Generic object (if there is a gene)
Args : (optional)
$gene -- an XML element for the annotation
$gname -- gene name
$id -- gene ID (not always the same as the name)
_has_CDS
Title : _has_CDS
Usage : my $cds = $self->_has_CDS
Function: internal getter/setter for CDS features
Returns : a Bio::SeqFeature::Generic transcript object (or nothing)
Args : a Bio::SeqFeature::Generic transcript feature
add_annotation
Title : add_annotation
Usage : $featHandler->add_annotation($seq, $type, $id, $tags, $feats)
Function: converts a containment hierarchy into an ordered list of flat features
Returns : nothing
Args : $seq -- a Bio::SeqI compliant object
$type -- the annotation type
$id -- the anotation ID
$tags -- ref. to a hash of tag/value attributes
$feats -- ref to an array of Bio::SeqFeature::Generic objects
_add_generic_annotation
Title : _add_generic_annotation
Usage : $self->_add_generic_annotation($seq, $type, $id, $tags, $feats)
Function: an internal method to handle non-gene annotations
Returns : nothing
Args : $seq -- a Bio::SeqI compliant object
$type -- the annotation type
$id -- the anotation ID
$tags -- ref. to a hash of tag/value attributes
$feats -- ref to an array of Bio::SeqFeature::Generic objects
feature_set
Title : feature_set
Usage : push @feats, $featHandler->feature_set($id, $gname, $set, $anntype);
Function: handles <feature_span> hierarchies (usually a transcript)
Returns : a list of Bio::SeqFeature::Generic objects
Args : $id -- ID of the feature set
$gname -- name of the gene
$set -- the <feature_set> object
$anntype -- type of the parent annotation
_build_feature_set
Title : _build_feature_set
Usage : $self->_build_feature_set($set, 1) # 1 flag means retain the exon as a subfeat
Function: an internal method to process attributes and subfeats of a feature set
Returns : nothing
Args : $set -- a <feature_set> element
1 -- optional flag to retain exons as subfeats. Otherwise, they will
be converted to sublocations of a parent CDS feature
_add_feature_span
Title : _add_feature_span
Usage : $self->_add_feature_span($el, 1)
Function: an internal method to process <feature_span> elements
Returns : nothing
Args : $el -- a <feature_span> element
1 -- an optional flag to retain exons as subfeatures
_add_CDS
Title : _add_CDS
Usage : my $cds = $self->_add_CDS($transcript, $tags)
Function: an internal method to create a CDS feature from a transcript feature
Returns : a Bio::SeqFeature::Generic object
Args : $transcript -- a Bio::SeqFeature::Generic object for a transcript
$tags -- ref. to a hash of tag/value attributes
#
#
# Helper module for Bio::SeqIO::game::featHandler
#
# Please direct questions and support issues to <bioperl-l@bioperl.org>
#
# Cared for by Sheldon McKay <mckays@cshl.edu>
#
# You may distribute this module under the same terms as perl itself
#
# POD documentation - main docs before the code
package Bio::SeqIO::game::featHandler;
use Bio::SeqFeature::Generic;
use Bio::Location::Split;
use Data::Dumper;
use strict;
use vars qw {};
use base qw(Bio::SeqIO::game::gameSubs);
sub new {
my ($caller, $seq, $seq_h, $ann_l ) = @_;
my $class = ref($caller) || $caller;
my $self = bless ({
seq => $seq,
curr_feats => [],
curr_coords => [],
seq_h => $seq_h,
ann_l => $ann_l,
}, $class);
return $self;
}
sub add_source {
my ($self, $length, $tags) = @_;
my $feat = Bio::SeqFeature::Generic->new( -primary => 'source',
-start => 1,
-end => $length,
);
for ( keys %{$tags} ) {
for my $val ( @{$tags->{$_}} ) {
$feat->add_tag_value( $_ => $val );
}
}
return $feat;
}
sub has_gene {
my ($self, $gene, $gname, $id) = @_;
# use name preferentially over id. We can't edit IDs in Apollo
# AFAIK, and this will create an orphan CDS for newly created
# transcipts -- I think this needs more work
#$id = $gname if $id && $gname;
unless ( $gene ) {
if ( defined $self->{curr_gene} ) {
return $self->{curr_gene};
}
else {
return 0;
}
}
else {
if ( $id && !$self->{curr_ltag} ) {
$self->{curr_ltag} = $id;
}
if ( $gname && !$self->{curr_gname} ) {
$self->{curr_gname} = $gname;
}
my $tags = {};
for my $child ( @{$gene->{Children}} ) {
my $name = $child->{Name};
if ( $name eq 'dbxref' ) {
$tags->{dbxref} ||= [];
push @{$tags->{dbxref}}, $self->dbxref( $child );
}
elsif ( $name !~ /name/ ){
$self->complain("Unrecognized element '$name'. I don't " .
"know what to do with $name elements");
}
}
my $feat = Bio::SeqFeature::Generic->new(
-primary => 'gene',
);
my %seen;
for ( keys %{$tags} ) {
for my $val ( @{$tags->{$_}} ) {
$feat->add_tag_value( $_ => $val ) unless ++$seen{$_.$val} > 1;
}
}
$self->{curr_gene} = $feat;
return $feat;
}
}
sub _has_CDS {
my ($self, $transcript) = @_;
if ( !$transcript ) {
if ( defined $self->{curr_cds} ) {
return $self->{curr_cds};
}
else {
return 0;
}
}
else {
my $tags = $self->{curr_tags};
$self->{curr_cds} = $self->_add_CDS( $transcript, $tags );
}
}
sub add_annotation {
my ($self, $seq, $type, $id, $tags, $feats) = @_;
# is this a generic feature?
unless ( $self->has_gene ) {
shift;
$self->_add_generic_annotation(@_);
return 0;
}
my $feat;
if ( $type eq 'gene' ) {
$feat = $self->has_gene;
$feat->add_tag_value( gene => ($self->{curr_gname} || $id) )
unless $feat->has_tag('gene');
}
else {
$feat = Bio::SeqFeature::Generic->new;
$feat->primary_tag($type);
my $gene = $self->has_gene;
$gene->add_tag_value( gene => ($self->{curr_gname} || $id) )
unless $gene->has_tag('gene');
$feat->add_tag_value( gene => ($self->{curr_gname} || $id) )
unless $feat->has_tag('gene');;
}
for ( keys %{$tags} ) {
# or else add simple tag/value pairs
if ( $_ eq 'name' && $tags->{type}->[0] eq 'gene' ) {
$feat->add_tag_value( gene => $tags->{name}->[0] )
unless $feat->has_tag( 'gene' );
delete $tags->{name};
}
else {
next if $_ eq 'type' && $tags->{$_}->[0] eq 'gene';
next if $_ eq 'gene' && $feat->has_tag( 'gene' );
for my $val ( @{$tags->{$_}} ) {
$feat->add_tag_value( $_ => $val );
}
}
}
$feat->strand( $self->{curr_strand} );
$feat->start( $self->{curr_coords}->[0] );
$feat->end( $self->{curr_coords}->[1] );
# create an array of features for the annotation (order matters)
my @annotations = ( $feat );
# add the gene feature if the annotation is not a gene
if ( $self->has_gene && $type ne 'gene') {
my $gene = $self->has_gene;
$gene->strand( $self->{curr_strand} );
$gene->start( $self->{curr_coords}->[0] );
$gene->end( $self->{curr_coords}->[-1] );
push @annotations, $gene;
$self->{curr_gene} = '';
}
# add the subfeatures
for ( @{$feats} ) {
$self->complain("bad feature $_") unless ref($_) =~ /Bio/;
push @annotations, $_;
}
# add the annotation array to the list for this sequence
my $seqid = $seq->id;
my $list = $self->{ann_l};
# make sure the feature_sets appear in ascending order
if ( $list->[0] && $annotations[0]->start < $list->[0]->start ) {
unshift @{$list}, @annotations;
}
else {
push @{$list}, @annotations;
}
# garbage collection
$self->{curr_gene} = '';
$self->{curr_ltag} = '';
$self->{curr_gname} = '';
$self->{curr_coords} = [];
$self->{curr_feats} = [];
$self->{curr_strand} = 0;
$self->{ann_seq} = $seq;
$self->flush;
}
sub _add_generic_annotation {
my ($self, $seq, $type, $id, $tags, $feats) = @_;
for ( @$feats ) {
$_->primary_tag($type);
}
push @{$self->{ann_l}}, @$feats;
$self->{curr_coords} = [];
$self->{curr_feats} = [];
$self->{curr_strand} = 0;
$self->{ann_seq} = $seq;
$self->flush;
}
sub feature_set {
my ($self, $id, $gname, $set, $anntype) = @_;
my $stype = $set->{_type}->{Characters};
$self->{curr_loc} = [];
$self->{curr_tags} = {};
$self->{curr_subfeats} = [];
$self->{curr_strand} = 0;
my @feats = ();
my $tags = $self->{curr_tags};
my $sname = $set->{_name}->{Characters} ||
$set->{Attributes}->{id};
if ( $set->{Attributes}->{problem} ) {
$tags->{problem} = [$set->{Attributes}->{problem}];
}
my @fcount = grep { $_->{Name} eq 'feature_span' } @{$set->{Children}};
if ( @fcount == 1 ) {
$self->_build_feature_set($set, 1);
my ($feat) = @{$self->{curr_subfeats}};
$feat->primary_tag('transcript') if $feat->primary_tag eq 'exon';
if ( $feat->primary_tag eq 'transcript' ) {
$feat->add_tag_value( gene => ($gname || $id) )
unless $feat->has_tag('gene');
}
my %seen_tag;
for my $tag ( keys %{$tags} ) {
for my $val ( @{$tags->{$tag}} ) {
$feat->add_tag_value( $tag => $val )
if $val && ++$seen_tag{$tag.$val} < 2;
}
}
@feats = ($feat);
}
else {
$self->{curr_ltag} = $id;
$self->{curr_cds} = '';
$gname = $id if $gname eq 'gene';
$self->{curr_gname} = $gname;
if ( $self->has_gene ) {
unless ( $anntype =~/RNA/i ) {
$stype =~ s/transcript/mRNA/;
}
}
$self->{curr_feat} = Bio::SeqFeature::Generic->new(
-primary => $stype,
-id => $id,
);
my $feat = $self->{curr_feat};
$self->_build_feature_set($set);
my $gene = $gname || $self->{curr_ltag};
$feat->add_tag_value( gene => $gene )
unless $feat->has_tag('gene');
# if there is an annotated protein product
my $cds = $self->_has_CDS( $feat );
if ( $cds ) {
$feat->primary_tag('mRNA');
# we really just want one value here
$cds->remove_tag('standard_name') if $cds->has_tag('standard_name');
$cds->add_tag_value( standard_name => $sname );
$cds->remove_tag('gene') if $cds->has_tag('gene');
$cds->add_tag_value( gene => $gene );
# catch empty protein ids
if ( $cds->has_tag('protein_id' ) && !$cds->get_tag_values('protein_id') ) {
my $pid = $self->protein_id($cds, $sname);
$cds->remove_tag('protein_id');
$cds->add_tag_value( protein_id => $pid );
}
# make sure other subfeats are tied to the transcript
# via a 'standard_name' qualifier and the gene via a 'gene' qualifier
my @subfeats = @{$self->{curr_subfeats}};
for my $sf ( @ subfeats ) {
$sf->add_tag_value( standard_name => $sname )
unless $sf->has_tag('standard_name');
$sf->add_tag_value( gene => $gene )
unless $sf->has_tag('gene');
}
$feat->add_tag_value( standard_name => $sname )
unless $feat->has_tag('standard_name');
$feat->add_tag_value( gene => $gene )
unless $feat->has_tag('gene');
# if the mRNA and CDS are the same length, the mRNA is redundant
# lose the mRNA, steal its tags and give them to the CDS
my %seen;
if ( $feat->length == $cds->length ) {
for my $t ( $feat->all_tags ) {
next if $t =~ /gene|standard_name/;
$cds->add_tag_value( $t => $feat->get_tag_values($t) );
}
undef $feat;
}
@feats = sort { $a->start <=> $b->start } ($cds, @subfeats);
unshift @feats, $feat if $feat;
}
else {
if ( @{$self->{curr_loc}} > 1 ) {
my $loc = Bio::Location::Split->new( -splittype => 'JOIN' );
# sort the exons in ascending start order
my @loc = sort { $a->start <=> $b->start } @{$self->{curr_loc}};
# then add them to the transcript location
for ( @loc ) {
$loc->add_sub_Location( $_ )
}
$feat->location( $loc );
}
else {
$feat->location( $self->{curr_loc}->[0] );
}
for ( keys %$tags ) {
# expunge duplicate gene attributes
next if /gene/ && $feat->has_tag('gene');
for my $v ( @{$tags->{$_}} ) {
$feat->add_tag_value( $_ => $v );
}
}
# make sure other subfeats are tied to the transcript
my @subfeats = @{$self->{curr_subfeats}};
for my $sf ( @ subfeats ) {
$sf->add_tag_value( standard_name => $sname )
unless $sf->has_tag('standard_name');
$sf->add_tag_value( gene => $gene )
unless $sf->has_tag('gene');
}
@feats = ( $feat, @subfeats );
}
}
# adjust the maximum extent of the annotated feature
# if req'd (ie the <annotation> element)
$self->{curr_coords}->[0] ||= 1000000000000;
$self->{curr_coords}->[1] ||= -1000000000000;
for ( @feats ) {
if ( $self->{curr_coords}->[0] > $_->start ) {
$self->{curr_coords}->[0] = $_->start;
}
if ( $self->{curr_coords}->[1] < $_->end ) {
$self->{curr_coords}->[1] = $_->end;
}
}
$self->flush( $set );
return @feats;
}
sub _build_feature_set {
my ($self, $set, $keep_subfeat) = @_;
for my $child ( @{$set->{Children}} ) {
my $name = $child->{Name};
# these elements require special handling
if ( $name eq 'date' ) {
$self->date( $child );
}
elsif ( $name eq 'comment' ) {
$self->comment( $child );
}
elsif ( $name eq 'evidence' ) {
$self->evidence( $child );
}
elsif ( $name eq 'feature_span' ) {
$self->_add_feature_span( $child, $keep_subfeat );
}
elsif ( $name eq 'property' ) {
$self->property( $child );
}
# need to add the db_xref tags to the gene?
# otherwise, simple tag/value pairs
elsif ( $name =~ /synonym|author|description/) {
$self->{curr_tags}->{$name} = [$child->{Characters}];
}
elsif ( $name !~ /name|type|seq/ ){
$self->complain("Unrecognized element '$name'. I don't " .
"know what to do with $name elements");
}
}
}
sub _add_feature_span {
my ($self, $el, $keep_subfeat) = @_;
my $tags = $self->{curr_tags};
my $feat = $self->{curr_feat};
my $type = $el->{_type}->{Characters} || $el->{Name};
my $id = $el->{Attributes}->{id} || $el->{_name}->{Characters};
my $seqr = $el->{_seq_relationship};
my $start = int $seqr->{_span}->{_start}->{Characters};
my $end = int $seqr->{_span}->{_end}->{Characters};
my $stype = $seqr->{Attributes}->{type};
my $seqid = $seqr->{Attributes}->{seq};
push @{$self->{seq_l}}, $self->{seq_h}->{$seqid};
if ( $start > $end ) {
$self->{curr_strand} = -1;
($start, $end) = ($end, $start);
}
else {
$self->{curr_strand} = 1;
}
# add exons to the transcript
if ( $type eq 'exon' ) {
my $sl = Bio::Location::Simple->new( -start => $start,
-end => $end,
-strand => $self->{curr_strand} );
push @{$self->{curr_loc}}, $sl;
}
# apollo and gadfly use different tags for the same thing
if ( $type =~ /start_codon|translate offset/ ) {
$self->{curr_tags}->{codon_start} = [$start];
}
else {
if ( $type eq 'exon' ) {
return unless $keep_subfeat;
}
push @{$self->{curr_subfeats}},
Bio::SeqFeature::Generic->new( -start => $start,
-end => $end,
-strand => $self->{curr_strand},
-primary => $type );
}
# identify the translation product
my $tscript = $el->{Attributes}->{produces_seq};
if ( $tscript && $tscript ne 'null') {
my $subseq = $self->{seq_h}->{$el->{Attributes}->{produces_seq}};
$self->{curr_tags}->{product} = [$el->{Attributes}->{produces_seq}];
$self->{curr_tags}->{translation} = [$subseq->seq] if $subseq;
}
$self->flush( $el );
}
sub _add_CDS {
my ($self, $feat, $tags) = @_;
my $loc = {};
my $single = 0;
if ( @{$self->{curr_loc}} > 1 ) {
$loc = Bio::Location::Split->new;
# sort the exons in ascending start order
my @loc = sort { $a->start <=> $b->start } @{$self->{curr_loc}};
# then add them to the location object
for ( @loc ) {
$loc->add_sub_Location( $_ );
}
}
else {
$loc = $self->{curr_loc}->[0];
$single++;
}
# create a CDS
my @exons = $single ? $loc : $loc->sub_Location(1);
$feat->location($loc);
# try to find a peptide
my $seq = $self->{seq_h}->{ $tags->{protein_id}->[0] };
$seq ||= $self->{seq_h}->{ $tags->{product}->[0] } ||
$self->{seq_h}->{ $tags->{gene}->[0] } ||
$self->{seq_h}->{ $tags->{standard_name}->[0] };
# Can we count on the description format being consistent?
# Why is CDS coordinate info saved as description text not
# specified in the DTD? Anyone have a better idea? Aww,
# who am I kidding, I'm the only one who will ever read this!
my ($start, $stop, $peptide) = ();
if ( $seq ) {
$peptide = $seq->display_id;
my $desc = $seq->description || '';
$desc =~ s/,|\n//g;
$desc =~ s/\)(\w)/\) $1/g;
if ( $desc =~ /cds_boundaries:.+?(\d+)\.\.(\d+)/ ) {
($start, $stop) = ($1 - $self->{offset}, $2 - $self->{offset});
}
else {
# OK, I guess the transcript must be the CDS then
$start = $loc->start;
$stop = $loc->end;
}
}
else {
$self->warn("I did not find a protein sequence for " . $feat->display_name);
}
delete $tags->{transcript};
# now chop off the UTRs to create a CDS
my @exons_to_add = ();
#warn scalar(@exons), " exons, $start, $stop\n";
for ( @exons ) {
my $exon = Bio::Location::Simple->new;
if ( $_->end < $start || $_->start > $stop ) {
#warn "exon out of range\n";
next;
}
if ( $_->start < $start && $_->end > $start ) {
#warn "chopping off left UTR\n";
$exon->start( $start );
}
if ( $_->end > $stop && $_->start < $stop ) {
#warn "chopping off right UTR\n";
$exon->end( $stop );
}
unless ($exon->valid_Location) {
$exon->start( $_->start );
$exon->end( $_->end );
}
$exon->strand ( $self->{curr_strand} );
push @exons_to_add, $exon;
}
my $cds_loc;
if ( @exons_to_add > 1 ) {
$cds_loc = Bio::Location::Split->new( -splittype => 'JOIN' );
for ( @exons_to_add ) {
$cds_loc->add_sub_Location( $_ );
}
}
else {
$cds_loc = $exons_to_add[0];
}
my $parent = $self->{curr_gname} || $self->{curr_ltag};
# try not to steal too many mRNA attributes for the CDS
my $cds_tags = {};
for my $k ( keys %$tags ) {
if ( $k =~ /product|protein|translation|codon_start/ ) {
$cds_tags->{$k} = $tags->{$k};
delete $tags->{$k};
}
}
for ( keys %$tags ) {
for my $v ( @{$tags->{$_}} ) {
$feat->add_tag_value( $_ => $v )
unless $feat->has_tag($_);
}
}
if ( $self->{curr_gname} ) {
$cds_tags->{gene} = [$self->{curr_gname}];
}
my $gene = $self->has_gene;
my $cds = Bio::SeqFeature::Generic->new(
-primary => 'CDS',
-location => $cds_loc,
);
$cds_tags->{translation} = [$seq->seq];
for ( keys %{$cds_tags} ) {
my %seen;
for my $val (@{$cds_tags->{$_}}) {
next if ++$seen{$val} > 1;
$cds->add_tag_value( $_ => $val );
}
}
$cds;
}
1;