Applied and Environmental Science

Using CRISPR-Cas as a Biological Tape Recorder

 

Researchers at Columbia University led by Ravi Sheth and Harris Wang have converted the immune system of Escherichia coli into a microscopic data recorder using CRISPR-Cas technology.  The new system allows E. coli to record its interactions with the environment and time-stamp the events.  Because the bacteria can monitor and record invisible changes without disrupting their surroundings, this technology could be used for disease diagnosis, environmental monitoring, and a host of so far undiscovered applications.

“Such bacteria, swallowed by a patient, might be able to record the changes they experience through the whole digestive tract, yielding an unprecedented view of previously inaccessible phenomena,” said Wang.  “The CRISPR-Cas system is a natural biological memory device.  From an engineering perspective, that’s actually quite nice because it’s already a system that has been honed through evolution to be really great at storing information.”

Wang explained that CRISPR-Cas normally uses its recorded sequences to detect and cut the DNA of phages that enter the body, and researchers have taken advantage of that ability to make precise changes in the genomes of cultured cells, lab animals, and human beings.  The recording system is housed in a “recording” plasmid that stays active all the time and regularly receives and records spacer sequences from the cell in which it lives.  This provides a background of time information.  When an external stimulus is detected, another type of plasmid is activated and inserts its sequences into the recorder plasmid to create a notation of the stimulus event.  Where it enters the background time sequences allows scientists to determine when the event took place by examining the bacterial CRISPR locus and using computational tools to read its information.

The team has also developed a multiplex strategy that can simultaneously record the availability of copper, trehalose, and fucose in a cell population over time.  This will allow researchers to measure dynamic cellular states and environmental changes, and enable the scientific community to chronicle biological events on a large scale.

Wang said that the team was planning to look at markers that can be altered by changes in natural and disease states inside and outside of the gastrointestinal system.  He added that synthetic biologists have previously used CRISPR to store poems, books, and images in DNA, but this is the first time it has been used to record cellular activity.

For more information, go to the November 23 issue of Science.

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1 Comment

Rockxstar Arham

2017-12-06 03:14:50

Informative News about science.