Hey all,

This script, connect to Ensembl API, gets the 500 bases upstream from the Transcription Start Site for Human transcript ID's.

How can i generalize this scripts to get the 500 bp for any organism?like: ENSCAFT00000017399, ENSPVAT00000009012, ENSECAT00000019626,ENSMPUT00000010176

#!/usr/bin/perl
use strict;
use warnings;
use Bio::EnsEMBL::Registry;

my $reg = 'Bio::EnsEMBL::Registry';

$reg->load_registry_from_db(
    -host => 'ensembldb.ensembl.org',
    -user => 'anonymous'
);


my $gene_adaptor = $reg->get_adaptor( "human", "core", "gene" );
# my $gene = $gene_adaptor->fetch_by_stable_id("ENST00000269844");
my $transcript_adaptor =  $reg->get_adaptor( 'Human', 'Core', 'Transcript' );
my $gene = $transcript_adaptor->fetch_by_stable_id("ENST00000269844");

#  get the slice adaptor
my $slice_adaptor = $reg->get_adaptor( "human", "core", "slice" );

# get the chromosome
my $chr = $gene->seq_region_name;

# one option if the gene is positive strand
if ($gene->seq_region_strand == 1){
    # In Ensembl, the "gene start" is always the smaller coordinate and the "gene end" is always the larger coordinate, regardless of the gene strand
    # this means that on the positive strand gene, the "gene start" will be the 5' end
    # to get the 500bp upstream, we want to end with the gene start, and start at gene start - 500
    my $slice_end = $gene->seq_region_start;
    my $slice_start = $slice_end - 500;


    my $slice = $slice_adaptor->fetch_by_region( "chromosome", $chr, $slice_start, $slice_end );
  my $sequence = $slice->seq();
  my $coord_sys  = $slice->coord_system()->name();
my $seq_region = $slice->seq_region_name();
my $start      = $slice->start();
my $end        = $slice->end();
my $strand     = $slice->strand();

print "Slice: $coord_sys $seq_region $start-$end ($strand)\n";
  print "$sequence\n";
    }

# another option if the gene is negative strand
else {

    # on the negative strand gene, the "gene end" will be the 5' end
    # to get the 500bp upstream, we want to start with the gene end and end at gene end + 500
    my $slice_start = $gene->seq_region_end ;
    my $slice_end = $slice_start + 500;

    my $slice = $slice_adaptor->fetch_by_region( "chromosome", $chr, $slice_start, $slice_end );
  my $sequence = $slice->seq();
  my $coord_sys  = $slice->coord_system()->name();
my $seq_region = $slice->seq_region_name();
my $start      = $slice->start();
my $end        = $slice->end();
my $strand     = $slice->strand();

print "Slice: $coord_sys $seq_region $start-$end ($strand)\n";
  print "$sequence\n";

    }