and mutations in mitochondrial DNA are known to cause almost 90 types of diseases. However, modern genetic technology lacks mitochondrial editing.
“There are some extremely nasty hereditary diseases arising due to defects in mitochondrial DNA. For example, Leber hereditary optic neuropathy (LHON), which causes sudden blindness in both eyes, is caused by a simple single point mutation in mitochondrial DNA.” “Another problem is that there is a dearth of animal models of these mitochondrial diseases. This is because it is currently not possible to engineer mitochondrial mutations necessary to create animal models. Lack of animal models makes it very difficult to develop and test therapeutics for these diseases,” says Director KIM Jin-Soo of the Center for Genome Engineering.
Although a scientific team by David R. LIU of the Broad Institute of Harvard and MIT had made a breakthrough discovery of a new base editor named DddA-derived cytosine base editors (DdCBEs perform base C-to-T conversion from DNA in mitochondria) in 2020, it had its limitations.
Breakthrough Genome Technology
Hence, the present discovery serves as a reliable technology to edit mitochondrial DNA (mtDNA) the last frontiers of genome engineering. Moreover, the TALEDs were found to be neither cytotoxic nor cause instability in mtDNA.
TALED consists the fusion of three different components a transcription activator-like effector (TALE that targets DNA sequence), TadA8e (an adenine deaminase for facilitating A-to-G conversion) and DddAtox (a cytosine deaminase that makes the DNA more accessible to TadA8e).
“I believe the significance of this discovery is comparable to the invention of blue LED, which was awarded a Nobel Prize in 2014. Just like how the blue LED was the final piece of the puzzle that allowed us to have a highly energy-efficient source of white LED light, it is expected that TALED will usher in a new era of genome engineering,” says William I. Suh, the science communicator at the Institute for Basic Science.
Source: Medindia
