Gene editing: CRISPR

The DNA in our cells forms the code that dictates how our bodies are organized and how the body works.   Recently, CRISPR (clustered regularly interspaced short palindromic repeats) technology has been used to clip out sections of DNA and insert new DNA.  A palindrome is a word that is the same spelled in either direction, such as madam. The palindromic repeats in DNA are convenient splicing points (and some have “sticky” ends) where DNA can be easily cut out and replaced with another DNA segment.

How the idea got started:  In viral infections of bacteria, it was learned that Cas proteins cut out samples of viral DNA which are then inserted into the host DNA, like a library.  There are Cas9 “monitors” that look at the library segment and if another incoming infection matches to the previous recorded infection, the new, identified viral intruder is destroyed.

In the lab, an RNA can be designed to match the area of a gene which is desired to be “edited.”  This RNA is then attached to a Cas9 (nuclease).  When introduced into the desired organism (host), the Cas9 then snips the DNA at the target site.  A “corrected” or “desired” gene can then be spliced into the cut section of DNA.

The suggestion is that even eye color could be changed with this technology!  One of the dilemmas facing scientists now with CRISPR, is that they have the ability to change the DNA in deadly mosquitoes. The CRISPR technology could be utilized to eliminate diseases carried by the mosquitoes, such as malaria.  There are many genetic diseases which might be cured with CRISPR technology.  The problem faced is that scientists don’t fully realize the environmental impact of the elimination of these undesired disease vectors. For instance, mosquitoes are a food source for many animals and their elimination could play havoc in the food chain.

There is an abundance of drama associated with CRISPR:

CRISPR patent dispute heard in federal court

Chinese CRISPR used to genetically engineer babies to be resistant to HIV

Recently, I reviewed a scientific article on CRISPR and its potential use in fighting HIV/AIDS as part of one of my Online Biology Master’s Degree courses through Clemson University.

Video link:  My perception of CRISPR | June 2018

Literature Cited in the video link above:

Shuai Liu, Qiankun Wang, Xiao Yu, Yilin Li, Yandan Guo, Zhepeng Liu, Fuyun Sun, Wei Hou, Chunmei Li, Li Wu, Deyin Guo & Shuliang Chen, “HIV-1 inhibition in cells with CXCR4 mutant genome created by CRISPR-Cas9 and piggyBac recombinant technologies,” Scientific Report 8, article number: 8573 (2018), accessed June 11, 2018, https://www.nature.com/articles/s41598-018-26894-4