3 votes

Expanding the brain. Literally.

1 comment

  1. skybrian
    Link
    From the blog post: [...] Here's the paper and commentary.

    From the blog post:

    A search for human de novo genes that had both lncRNA homologues in monkeys and had such mutations that could lead to nuclear exit turned up 29 genes that are shared between humans and chimpanzees, and 45 that are exclusively human. A closer look at nine of these that are known to be active in central nervous system tissue showed that their expression affects the size of cortical organoids grown from stem cells in culture (their overexpression makes these cultured neuron clumps grow somewhat larger, and their absence makes them smaller). The authors then inserted these gene sequences into mice, which animals showed “significant cortical expansion” as they matured. The Science commentary linked to above features a statement from one of the paper’s authors that a paper is coming that shows that these animal do indeed perform better in tests of cognitive function and memory. They are smarter mice, with larger brains. And now the hair may be rising up on the back of your neck, as it did on mine.

    [...]

    There are a number of very obvious experiments suggested by this work that we are going to have to be very cautious with. What happens if you splice a suite of these human-brain-only genes into mice, instead of just one at a time? What happens if you increase expression of one or more of them, with a different promoter or through adding more than one copy? We are going to be having some very interesting debates about quantifying animal intelligence. And we will want to practice very good laboratory hygiene as well, because I think we can all agree that it is not in our best interest to allow the earth’s mice and rats to become any more intelligent and wily than they are already. I wish that I were joking about that, but I’m not.

    Nor am I joking when I think about the human implications. As the world knows, we have already seen irresponsible attempts to do germline editing and produce altered human babies. When will someone try adding in more of the cortical-expansion genes, to see what happens? I’ll leave it there.

    Here's the paper and commentary.

    1 vote