NAME

Bio::SeqFeature::Gene::Exon - a feature representing an exon

SYNOPSIS

# obtain an exon instance $exon somehow
print "exon from ", $exon->start(), " to ", $exon->end(),
      " on seq ", $exon->seq_id(), ", strand ", $exon->strand(),
      ", encodes the peptide sequence ", 
      $exon->cds()->translate()->seq(), "\n";

DESCRIPTION

This module implements a feature representing an exon by implementing the Bio::SeqFeature::Gene::ExonI interface. By default an Exon is coding. Supply -is_coding => 0 to the constructor or call $exon->is_coding(0) otherwise.

Apart from that, this class also implements Bio::SeqFeatureI by inheriting off Bio::SeqFeature::Generic.

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

Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:

http://bugzilla.open-bio.org/

AUTHOR - Hilmar Lapp

Email hlapp@gmx.net

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

is_coding

Title   : is_coding
Usage   : if($exon->is_coding()) {
                  # do something
          }
          if($is_utr) {
              $exon->is_coding(0);
          }
Function: Get/set whether or not the exon codes for amino acid.
Returns : TRUE if the object represents a feature translated into protein,
          and FALSE otherwise.
Args    : A boolean value on set.

primary_tag

Title   : primary_tag
Usage   : $tag = $feat->primary_tag()
          $feat->primary_tag('exon')
Function: Get/set the primary tag for the exon feature.

          This method is overridden here in order to allow only for
          tag values following a certain convention. For consistency reasons,
          the tag value must either contain the string 'exon' or the string
          'utr' (both case-insensitive). In the case of 'exon', a string
          describing the type of exon may be appended or prefixed. Presently,
          the following types are allowed: initial, internal, and terminal
          (all case-insensitive). 

          If the supplied tag value matches 'utr' (case-insensitive),
          is_coding() will automatically be set to FALSE, and to TRUE
          otherwise.

Returns : A string.
Args    : A string on set.

location

 Title   : location
 Usage   : my $location = $exon->location()
 Function: Returns a location object suitable for identifying the location 
	   of the exon on the sequence or parent feature.

           This method is overridden here to restrict allowed location types
           to non-compound locations.

 Returns : Bio::LocationI object
 Args    : none

cds

Title   : cds()
Usage   : $cds = $exon->cds();
Function: Get the coding sequence of the exon as a sequence object.

          The sequence of the returned object is prefixed by Ns (lower case)
          if the frame of the exon is defined and different from zero. The
          result is that the first base starts a codon (frame 0).

          This implementation returns undef if the particular exon is
          not translated to protein, i.e., is_coding() returns FALSE. Undef
          will also be returned if no sequence is attached to this exon
          feature.

Returns : A Bio::PrimarySeqI implementing object.
Args    :