Monday, July 17, 2017

The Gallsitel-King conjecture; another brick in the wall

Several people sent me this piece discussing some recent work showing how to store and retrieve information in "live" (vs synthetic) DNA.  It's pretty cool. Recall the Gallistel-King conjecture (GKC) is that a locus of cognitive computing will be intra-cellular and that large molecules like DNA will be the repository of memories. The advantage is that we know how to"write to" and "read from" such chemical computers and that this is what we need if we are to biologically model the kinds of computations that behavioral studies have shown to be what is going on in animal cognition. The proof of concept that this is realistic invites being able to do this in "live" systems. This report shows that it has been done.

The images and videos the researchers pasted inside E. Coli are composed of black-and-white pixels. First, the scientists encoded the pixels into DNA. Then, they put their DNA into the E. coli cells using electricity. Running an electrical current across cells opens small channels in the cell wall, and then the DNA can flow inside. From here, the E. Coli’s CRISPR system grabbed the DNA and incorporated it into its own genome. “We found that if we made the sequences we supplied look like what the system usually grabs from viruses, it would take what we give,” Shipman says.
Once the information was inside, the next step was to retrieve it. So, the team sequenced the E. coli DNA and ran the sequence through a computer program, which successfully reproduced the original images. So the running horse you see at the top of the page is really just the computer's representation of the sequenced DNA, since we can’t see DNA with the naked eye.

Now we need to find more plausible mechanisms by which this kind of process might take place. But, this is a cool first step and makes the GKC a little less conjectural.

1 comment:

  1. In related news, this recent paper is also quite interesting against the background of the Gallistel-King conjecture: 10.1073/pnas.1621132114 . Information storage capacity of individual cells seems to be greater than widely assumed.