4 ms·

yes. I know a bit of neuroscience 101 and the abstract is greek to me. any1 got an ELI5? Sounds like a cool finding.

bglazer 3y ago
This isn’t exactly my area of expertise, but I know some of the jargon. Anyways, grain of salt, some details may be incorrect. Brain cells, and many other cell types communicate by releasing vesicles, which are very small bubbles of the cell’s membrane. These vesicles contain cargo, proteins or RNA, which generally function as signals of the cell’s state. These authors have engineered a pretty clever system for tracking when brain cells exchange these vesicles. First they insert two genes into mice. The first is called tdTomato and is a red fluorescent protein. Crucially, they insert this gene backwards. I’ll explain that in a second. Directly on either side of this gene, they also include a specific section of DNA called a LoxP site. This LoxP site is recognized by a protein called Cre. Cre binds to two LoxP sites, pulls them together, cuts out the DNA between them, flips the direction of the DNA, then reinserts it backwards. So, normally the backwards tdTomato can’t be expressed as a protein, but if Cre protein is introduced, it will flip the tdTomato and suddenly the cell will start generating this red fluorescing protein. The authors also engineered a virus to carry the Cre protein. Specifically they chose a lentivirus, which inserts its own genome into its host’s genome. Here this means the virus inserts the DNA encoding the Cre protein. They injected this virus into one area of the mouse brain, the striatum. Now the striatum cells express Cre, flip the tdTomato, and glow red. The lentivirus is not capable of expanding, so it stays isolated to the injection site in the striatum. But, the most important part is that the striatum cells also sometimes package up Cre mRNA in their vesicles. They export those vesicles and other brain cells take them up. Then those other brain cells express the Cre, and as a result, glow a pleasing 581nm wavelength red. This tells the authors that red glowing cells received a vesicle from a cell in the striatum. Very clever! As on example of an application, this could help scientists better understand how brain tumor cells are affecting other cells in the brain through vesicles.
- arto 3y ago
  Thanks for the nice summary!
- mywacaday 3y ago
  [flagged]
  - bglazer 3y ago
    I’m confused by your comment. The chatgpt output is basically just a restatement of the abstract. Does it make you have doubts about my summary?
    - mywacaday 3y ago
      Not at all, I was just interested to see what chat gpt would do compared to a knowledgeable person. That prompted me to think why would I trust a random stranger over chat gpt.
- Brian_K_White 3y ago
  "Cre binds to two LoxP sites, pulls them together, cuts out the DNA between them, flips the direction of the DNA, then reinserts it backwards." A protein does all that? We are cisc processors!
  - Doxin 3y ago
    Proteins do everything. Proteins are basically organic nanobots. It's some really wild stuff.
    - Brian_K_White 3y ago
      "Proteins do everything" is not what I found remarkable. "_A_ protein does all that" is. Or by "proteins do everything" do you mean to say that single proteins often do complex operations like that? I don't find it remarkable that complex operations get done. I just assumed the operations were built out of smaller and simpler steps. That was a pretty complex sounding operation that I would have thought involved at least 3 or 4 different steps performed by different molecules, one that locates, one that cuts, one that rotates, one that joins, etc.
      - Doxin 3y ago
        There's all sorts. There's definitely proteins that do single steps like that, but also proteins that do more complex sequences of steps. Sometimes the more complex proteins are assisted by signaling proteins and whatnot. I can't recommend getting "The machinery of life" enough. It's an incredible book with a lot of pictures explaining all this sort of thing. It gives you quite a good intuitive understanding of the chaotic environment inside cells.

This isn’t exactly my area of expertise, but I know some of the jargon. Anyways, grain of salt, some details may be incorrect. Brain cells, and many other cell types communicate by releasing vesicles, which are very small bubbles of the cell’s membrane. These vesicles contain cargo, proteins or RNA, which generally function as signals of the cell’s state. These authors have engineered a pretty clever system for tracking when brain cells exchange these vesicles. First they insert two genes into mice. The first is called tdTomato and is a red fluorescent protein. Crucially, they insert this gene backwards. I’ll explain that in a second. Directly on either side of this gene, they also include a specific section of DNA called a LoxP site. This LoxP site is recognized by a protein called Cre. Cre binds to two LoxP sites, pulls them together, cuts out the DNA between them, flips the direction of the DNA, then reinserts it backwards. So, normally the backwards tdTomato can’t be expressed as a protein, but if Cre protein is introduced, it will flip the tdTomato and suddenly the cell will start generating this red fluorescing protein. The authors also engineered a virus to carry the Cre protein. Specifically they chose a lentivirus, which inserts its own genome into its host’s genome. Here this means the virus inserts the DNA encoding the Cre protein. They injected this virus into one area of the mouse brain, the striatum. Now the striatum cells express Cre, flip the tdTomato, and glow red. The lentivirus is not capable of expanding, so it stays isolated to the injection site in the striatum. But, the most important part is that the striatum cells also sometimes package up Cre mRNA in their vesicles. They export those vesicles and other brain cells take them up. Then those other brain cells express the Cre, and as a result, glow a pleasing 581nm wavelength red. This tells the authors that red glowing cells received a vesicle from a cell in the striatum. Very clever! As on example of an application, this could help scientists better understand how brain tumor cells are affecting other cells in the brain through vesicles.

arto 3y ago
Thanks for the nice summary!
mywacaday 3y ago
[flagged]
- bglazer 3y ago
  I’m confused by your comment. The chatgpt output is basically just a restatement of the abstract. Does it make you have doubts about my summary?
  - mywacaday 3y ago
    Not at all, I was just interested to see what chat gpt would do compared to a knowledgeable person. That prompted me to think why would I trust a random stranger over chat gpt.
Brian_K_White 3y ago
"Cre binds to two LoxP sites, pulls them together, cuts out the DNA between them, flips the direction of the DNA, then reinserts it backwards." A protein does all that? We are cisc processors!
- Doxin 3y ago
  Proteins do everything. Proteins are basically organic nanobots. It's some really wild stuff.
  - Brian_K_White 3y ago
    "Proteins do everything" is not what I found remarkable. "_A_ protein does all that" is. Or by "proteins do everything" do you mean to say that single proteins often do complex operations like that? I don't find it remarkable that complex operations get done. I just assumed the operations were built out of smaller and simpler steps. That was a pretty complex sounding operation that I would have thought involved at least 3 or 4 different steps performed by different molecules, one that locates, one that cuts, one that rotates, one that joins, etc.
    - Doxin 3y ago
      There's all sorts. There's definitely proteins that do single steps like that, but also proteins that do more complex sequences of steps. Sometimes the more complex proteins are assisted by signaling proteins and whatnot. I can't recommend getting "The machinery of life" enough. It's an incredible book with a lot of pictures explaining all this sort of thing. It gives you quite a good intuitive understanding of the chaotic environment inside cells.