Why in News? 

Scientists have developed a smart molecular tool to help plants cope with heat and infections, as stress from extreme weather or microbes reduces their productivity. 

CRISPR/Cas9 – Gene Editing Technology  

What is CRISPR? 

• CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. 
• It is a gene-editing technology used to remove, add, or alter parts of the DNA sequence of specific genes. 

What does it do? 

• CRISPR allows quick, low-cost and precise editing of genes. 
• It can correct genetic errors and regulate genes in cells and organisms. 

How was it developed? 

• Inspired by a natural defense system in bacteria. 
• Bacteria cut virus DNA and keep bits of it to recognize future attacks. 
• Scientists adapted this process for targeted DNA editing. 

Components of CRISPR-Cas9 System 

• Cas9 enzyme: Acts as molecular scissors to cut both strands of DNA at a specific site. 
• Guide RNA (gRNA) 
  • Has a 20-base sequence that guides Cas9 to the exact DNA location. 
  • Ensures Cas9 cuts the correct segment of DNA. 

Applications 

• Potential use in treating diseases with a genetic link such as, 
  • Cancer 
  • Hepatitis B 
  • High cholesterol