This article, though hard to
understand because of the prolixity and complexity of the subject matter, is
still very fascinating! The main focus of the article was to discuss the bright
future, and existing challenges of clustered regularly interspaced short
palindromic repeat (CRISPR) technology and the importance of developing
customizable specificities, such as CAS9, to improve its capabilities. This technology, when mastered, will enable
scientist to target specific gene mutations in DNA, cut out the faulty sequence
and insert the correct sequence, thus curing the genetic disease. Even more exciting, scientists are currently
creating large Guided-RNA (gRNA) libraries which will not only be able to target
one specific gene mutation, but THOUSANDS all at once! These libraries
currently contain about 67,000 to 84,000 separate distinct gRNA’s and have
shown to be effective phenotype screens in both human and mouse cells! This biggest obstacle that the CRISPR-CAS9 developers
are facing right now is the effects of “off-target” effects. “Off-target” effects are defined as nucleotide
cleaving at an unintended site of the DNA.
So far, they have found that these effects are much more detrimental if
they occur at the 5’-end rather than the 3’-end. So far, the best strategy for
preventing these negative effects is to lower the concentration of the gRNA
and/or CRISPR-CAS9 being expressed in the human cells. I, for one, am very excited to see where this
technology leads us! https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4022601/
