Is there a way to compare two nucleotide sequences in Linux via command line tools such as diff

Question

I have two genomic sequences that I want to compare letter by letter. They share almost the same pattern but some nucleotide transitions occur.

For example

Sequence 1

ATGGCGATGAGCAGCGGCGGCAGTGGTGGCGGCGTCCCGGAGCAGGAGGATTCCGTGCTGTTCCGGCGCGGCACAGGCCAGAGCGATGATTCTGACATTTGGGATGATACAGCACTGATAAAAGCATATGATAAAGCTGTGGCTTCATTTAAGCATGCTCTAAAGAATGGTGACATTTGTGAAACTTCGGGTAAACCAAAAACCACACCTAAAAGAAAACCTGCTAAGAAGAATAAAAGCCAAAAGAAGAATACTGCAGCTTCCTTACAACAGTGGAAAGTTGGGGACAAATGTTCTGCCATTTGGTCAGAAGACGGTTGCATTTACCCAGCTACCATTGCTTCAATTGATTTTAAGAGAGAAACCTGTGTTGTGGTTTACACTGGATATGGAAATAGAGAGGAGCAAAATCTGTCCGATCTACTTTCCCCAATCTGTGAAGTAGCTAATAATATAGAACAAAATGCTCAAGAGAATGAAAATGAAAGCCAAGTTTCAACAGATGAAAGTGAGAACTCCAGGTCTCCTGGAAATAAATCAGATAACATCAAGCCCAAATCTGCTCCATGGAACTCTTTTCTCCCTCCACCACCCCCCATGCCAGGGCCAAGACTGGGACCAGGAAAGCCAGGTCTAAAATTCAATGGCCCACCACCGCCACCGCCACCACCACCACCCCACTTACTATCATGCTGGCTGCCTCCATTTCCTTCTGGACCACCAATAATTCCCCCACCACCTCCCATATGTCCAGATTCTCTTGATGATGCTGATGCTTTGGGAAGTATGTTAATTTCATGGTACATGAGTGGCTATCATACTGGCTATTATATGGGTTTCAGACAAAATCAAAAAGAAGGAAGGTGCTCACATTCCTTAAATTAA

Sequence 2

ATGGCGATGAGCAGCGGCGGCAGTGGTGGCGGCGTCCCGGAGCAGGAGGATTCCGTGCTGTTCCGGCGCGGCACAGGCCAGAGCGATGATTCTGACATTTGGGATGATACAGCACTGATAAAAGCATATGATAAAGCTGTGGCTTCATTTAAGCATGCTCTAAAGAATGGTGACATTTGTGAAACTTCGGGTAAACCAAAAACCACACCTAAAAGAAAACCTGCTAAGAAGAATAAAAGCCAAAAGAAGAATACTGCAGCTTCCTTACAACAGTGGAAAGTTGGGGACAAATGTTCTGCCATTTGGTCAGAAGACGGTTGCATTTACCCAGCTACCATTGCTTCAATTGATTTTAAGAGAGAAACCTGTGTTGTGGTTTACACTGGATATGGAAATAGAGAGGAGCAAAATCTGTCCGATCTACTTTCCCCAATCTGTGAAGTAGCTAATAATATAGAACAGAATGCTCAAGAGAATGAAAATGAAAGCCAAGTTTCAACAGATGAAAGTGAGAACTCCAGGTCTCCTGGAAATAAATCAGATAACATCAAGCCCAAATCTGCTCCATGGAACTCTTTTCTCCCTCCACCACCCCCCATGCCAGGGCCAAGACTGGGACCAGGAAAGCCAGGTCTAAAATTCAATGGCCCACCACCGCCACCGCCACCACCACCACCCCACTTACTATCATGCTGGCTGCCTCCATTTCCTTCTGGACCACCAATAATTCCCCCACCACCTCCCATATGTCCAGATTCTCTTGATGATGCTGATGCTTTGGGAAGTATGTTAATTTCATGGTACATGAGTGGCTATCATACTGGCTATTATATGGAAATGCTGGCATAG

Is there a bash way to compare the sequence and colorize or print the differences?

EDIT: I want to compare gene sequence by means of linux tools.

I need line by line comparison of letters and highlighting the differences. I think diff is not good at comparing single word which formed of hundreds of letters.

Answer 1

You can save each line a separate file, e.g.

f1 - 1st genomic sequence f2 - 2nd genomic sequence

Now, you need to transform the lines (horizontal to vertical):

awk '{gsub(".","&\n");printf "%s",$0}' < f1 >f1a
awk '{gsub(".","&\n");printf "%s",$0}' < f2 >f2a

This will save the new format in 2 new files ( f1a and f2a ) Now compare the 2 files with diff

diff -y f1a f2a  #will output both lines and show differences
diff -c f1a f2a  #will only output the differences and tell you from which line to which line

More on diff: http://man7.org/linux/man-pages/man1/diff.1.html

The above can also made into a small script, where you could pass the 2 genomic sequences as variables.

If you want colored output, try using colordiff (In Ubuntu: sudo apt-get install colordiff) and just replace diff with colordiff in the script below. For side by side output, use option -y:

#!/bin/bash
# This script will compare the 2 genomic sequences
echo "1st genomic sequence, followed by [ENTER]:"
read gena
echo "2nd genomic sequence, followed by [ENTER]:"
read genb
echo $gena | awk '{gsub(".","&\n");printf "%s",$0}' > /tmp/fa
echo $genb | awk '{gsub(".","&\n");printf "%s",$0}' > /tmp/fb
echo "Insert the diff argument you wish to use (e.g. -y or -c). Please refer to man diff for information. Hit [ENTER]:"
read $arg
diff $arg /tmp/fa /tmp/fb
exit