Advent of recombinant DNA technology paved way towards genome editing. Since then, genome editing technology evolved steadily with consistent improvisation of the former technology. One such improvised technology was CRISPR-Cas9 which exploited the microbial adaptive immune system – CRISPR – found in bacteria and archaea. It provides acquired immunity against foreign viruses and plasmids. It was initially found in the E.coli K12 bacterial genome as repeated motifs of <50bp that were neatly and consistently ordered. At that time, it was considered to be “exotic junk of DNA”. Later, in the year 2002, this junk of DNA was named as Clustered Regularly Interspaced Short Palindromic Repeat’ – CRISPR.
by Ranjani Rajasekaran1 and J. John Kirubaharan2
1PhD scholar, 2Professor and Head,
Department of Veterinary Microbiology, Madras Veterinary College, Chennai –India.