A recent study in the journal Nature has provided proof of principle for a novel method which enables the encoding of a cell’s history in its genome and the subsequent readout of the information. Called MEMOIR (Memory by Engineered Mutagenesis with Optical In situ Readout), the new technique provides insight into cellular patterns of communication, relationships between cells, and various other events of influence, reaching beyond the static view of cells that is typically obtained.
In the current study, researchers used two tools to track changes in the cellular genome. Sequential single molecule Fluorescence In Situ Hybridization (seqFISH) provides insight into which specific genes are active in a particular cell. The second technique, the now famous CRISPR, facilitates genome editing via a DNA slicing system. Together, the two tools were used to create a unique genome memory storage element, much like a computer bit, which has two distinct states and can be assessed for shared CRISPR edits using seqFISH and fluorescence microscopy.
DNA cell lineage tracking provides important information about cell and tissue development, including that of abnormal tissues such as tumors. Though the current study used MEMOIR to track the cellular history of murine embryonic stem cells over several generations, the technique has the potential to provide insight into cell lineages across many generations, as well as tissue development and historical cellular events. Future applications may include the tracking of several signaling pathways in individual cells as well as for the study of tumorigenesis and metastases.