Analyzing biological phenomena is often difficult to accomplish, even with modern technology. In many cases, for the actions of small biomolecules and other hard to see functioning parts of a cell, we can only take snapshots that tell us a moment in time. But that’s not all that helpful for understanding the actions of enzymes or other proteins over the course of their activity and it leaves scientists largely in the dark guessing on how these functions proceed.
How To Go Beyond DNA
Technologies like CRISPR have already begun to help somewhat in that respect, like a previous Bioscription article that discussed using CRISPR to image the activities of individual genes and even many genes all at once.
But CRISPR is inherently a DNA (and sometimes RNA) focused tool. It only acts upon the genome itself and any invading viral genetic material. How could it be used to view other parts of a cell, such as biomolecule activity outside of the nucleus, if not elsewhere? That’s been the question for some time.
Last year, someone came up with, at least a partial, solution to this conundrum. Using certain parts of the CRISPR system, scientists at the Wyss Institute at Harvard were able to make a “molecular recorder” capable of recording biological information directly into the DNA of the genome. Then, it could be read back later and interpreted. The device, however, was still in its infancy and it wasn’t known if it would work at all, let alone of the hundreds of sequences and events it was desired to be used for all at once.
Inserting A Video
Effort into improving the recorder has continued though and in a recent study in the journal Nature they unveiled a new accomplishment with it. While it still lacks a confirmed ability to record complex biological events, it can encode DNA information given to it, even complicated sequences related to real world things.
With this in mind, the researchers modified the two CRISPR proteins involved in inserting viral DNA information, called Cas1 and Cas2, and used them to take up DNA sequences that related to the black and white pixels of a chosen video clip, an iconic one involving a running horse. This information also contained the frame number of the video, meaning subsequent pixels from later frames can also be added in sequence and read off of the genome in order to reconstruct the video.
In the process, they learned a large amount about what the rules are for spacer integration and how best to select sequences for them to be taken up by the CRISPR system. The research also showed that a significant amount of information can be added into the spacer part of the bacterial genome, enough to be practical for their ultimate plans with it.
Genetic Memory And DNA Databases
Their primary goal remains to use this modified tool to automatically record data on events within the cells, up to and including full differentiation of a human cell from being a stem cell to its final form. Understanding how these and other processes work is critical to fields like regenerative medicine and disease research.
And this creation may ultimately be used for far, far more, including efforts into storing real information into bacteria as a sort of biological database. Indeed, bio-digitization is fast becoming its own field of research and study that may discover and utilize these tools in ways that aren’t yet even thought of.
We’ll have to wait and see. But, for now, the main goal of these Harvard scientists is an admirable and critical one and it is hopeful that their new CRISPR-based tool will be successful in its attempt to have cells report about their own life experiences themselves.
Photo CCs: Neural Stem Cells and Growth Hormone Receptor from Wikimedia Commons