CRISPR: Redefining the Future of Human Health

CRISPR, or Clustered Regularly Interspaced Palindromic Repeats, are segments of DNA that are naturally found in many bacteria and form the basis of the immune system protecting organisms from foreign elements and viruses (Makarova, 67). These CRISPR sequences contain palindromic sequences with “spacer” sequences from viral infections, which allow the bacteria to “remember” the foreign invading DNA (Morange, 221). The CRISPR-associated (Cas) proteins help the CRISPR sequences recognize and cut complementary sequences, thus neutralizing the danger efficiently from the viral genome.

Discovered in the late 1980s (Morange, 221), CRISPR systems have been extensively researched, allowing scientists to classify CRISPR-Cas into various types based on their functional molecules and genetic composition. Currently, we understand that there are two main classes: Class 1, which includes multi-protein effector complexes, and Class 2, where there is a single, multi-effector protein, as seen with Cas9 (Makarova, 68). Due to advancements in current research, the number of classes discovered has gone from five types and sixteen subtypes to six types and thirty-three subtypes.

Throughout time, technology has evolved in biotechnology by utilizing shorter guide RNAs to direct the Cas9 enzyme to the specific DNA sequence where the cut is intended to occur. As opposed to previous genome editing tools such as ZFNs (Zinc Finger Nucleases), which utilize opposite DNA strands to “cut,” or TALENs (Transcription Activator-Like Effector Nucleases), which use DNA-binding domains to cut DNA at the target site, CRISPR-Cas 9 sends the RNA molecules, guiding the Cas9 enzyme to a specific DNA sequence (Severi & Akbari, 2). CRISPR-Cas9 is derived from a bacterial adaptive immune system, allowing for a more precise cut at the targeted DNA site. Due to this innovative breakthrough in the field of biotechnology, CRISPR has since broadened its scope in various fields, including agriculture, therapeutic research, and diagnostics, as it is substantially more affordable and efficient compared to previous methods, such as TALENs and ZFNs.