Researchers Converted Human Gut Bacteria into World’s Tiniest Data Recorder using Random Molecular Hacks.
US-based Columbia University Medical Center (CUMC) researchers have managed to modify the natural immune system of Escherichia coli, a human gut bacterium, to create world’s smallest Tape recorder. Escherichia coli can monitor invisible changes, but through this modification, it could record researchers’ interactions with the environment as well as time-stamp all the observed events. The study has been published in Science journal.
According to Harris Wang, senior author of the study, the abovementioned bacteria when swallowed by a patient starts recording the changes in the entire digestive tract and ultimately offers an “unprecedented view of the previously inaccessible phenomena.” All that the researchers had to do was to teach the bacteria about recording data and to fulfill this objective; they created microscopic data recorder.
It was created using the “natural biological memory device” known as CRISPR-Cas. It is built-in immune system found in the majority of bacterium species. This system can copy DNA snippets after attacking viruses to ensure that the forthcoming bacteria generations could resist the pathogens and destroy them effectively. Recorded sequences are used by CRISPR-Cas to identify and cut the incoming phages DNA.
This ability of CRISPR-Cas was harnessed previously by researchers of gene therapy for editing the genomes of not just cell cultures and lab animals but also humans for identification of advanced treatment options for diseases. Ravi Sheth, the co-author of the paper and graduate student in Wang’s lab, noted that CRISPR-Cas could perform versatile functions.
Researchers modified Plasmids, tiny circles of DNA present in bacteria, for recording the time and events; a separate recording plasmid monitored the time by adding spacers to its genome continually which depicted that if the bacteria is exposed to the right stimuli then the signal will interrupt the time to record spacer signal and inform when the event occurred.
When the external signal is absent, and just the recording plasmid is active, the cell adds copies of spacer sequence to the genome’s CRISPR-Cas locus. When the cell detects an external signal, then the plasmid also gets activated and starts inserting its sequences leading to the creation of a mixture of background sequences with the capability of recording time and signal sequences that change according to the modification in the cell’s environment. Currently, this system can handle three signals simultaneously and record for multiple days.
This is indeed a groundbreaking feat because it will pave the way for a completely new domain of technologies that would use bacterial cells for performing a range of tasks from diagnosing diseases to monitoring environmental fluctuations. Until now, synthetic biologists had used CRISPR for storing images, poems, and books in DNA and for the first time this system has been used for recording and monitoring of cellular activity.
Dr. Wang wrote that through this discovery it is now possible to explore other markets that can be modified with changes in natural or disease states such as in the gastrointestinal system. This video shows the entire process in detail.