#!/usr/bin/perl -w

print "The DNA sequence is : \n" ;
my $seq = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA';

print "$seq \n";
mutate ($seq);
print "\n";
exit;

sub mutate{
my($dna) = @_;
my $position = randposition($dna);


for ($i =0;$i<length($dna);$i++){

	if ($i == $position){

print " mutation at  base position ". ($position+1) . "\n";
	do {
	$nucleotide = randombase();

 	} until ($nucleotide ne substr($dna,$position,1));
	substr($dna, $position, 1, $nucleotide);

	print "$dna\n";
	}
$i++;
}


}

sub randposition{
my($sequence) = @_;
return int rand length($sequence);
}

sub randombase{

my(@nucleo) =('A','T','C','G');
return $nucleo[rand(@nucleo)];
}