Basel – Scientists at the ETH Zurich’s Department of Biosystems in Basel have developed a storage mechanism that can provide insight into the history of cellular processes. It is the first device of its kind.
Environmental influences or infections by viruses change the activity of genes in bacteria cells, explained the Basel Department of Biosystems (D-BSSE), which belongs to the Federal Institute of Technology in Zurich (ETH). These transcription processes and gene activity happen mainly at the level of mRNA molecules – but because these cells degrade after a short time, scientists have long been seeking a way to gain comprehensive information about the history of a bacteria cell. Now, Basel scientists have succeeded.
Using the CRISPR-Cas system, the researchers produced a molecular recording system. In the system, transcription incidents are stored as circular DNA molecules (plasmids), with this genetic information then recorded in a specific stretch of DNA known as a CRISPR array. CRISPR arrays are also capable of storing short sequences of DNA, known as spacers, originating from a pathogen. Spacers from different pathogens are separated from each other by DNA sequences.
To be of use, the information must first be converted in a process of several steps to give stable DNA fragments in chronological order. It can then be transferred from one generation of bacteria to the next.
“Our system is a biological data logger. It records the genetic response of bacteria to external influences and enables us to access that information even after many bacterial generations,” commented Florian Schmidt, lead author of the study, which was conducted by researchers working under Randall Platt of the D-BSSE.
Platt added: “Researchers have been working on creating forms of synthetic cellular memory for a long time, but we are the first to develop one that can record information about the expression of each gene in a cell over time.”