Scientists discovered that removing specific molecules from developing mice can completely reverse their sex from male to female.

  • tal@lemmy.todayOP
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    6 months ago

    While the study has only been done in mice, the six key microRNAs are found in all vertebrates and date back to the first vertebrates, about 500 million years ago. Therefore, it is very likely that this cluster of microRNAs works similarly in other mammals, as well — including humans.

    So, we probably now have the technical ability to genetically engineer the sex of a mammal.

    • Billiam@lemmy.world
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      6 months ago

      So, we probably now have the technical ability to genetically engineer the sex of a mammal.

      That’s probably stretching it a bit far- more like, we’re on the way to maybe be able to do that.

      The best the researchers were able to do was revert the development of a male fetus back into a female fetus, but the mice still kept their XY chromosomes. What happens if they try to bond these micro-RNAs to XX-chromosome mice fetuses? How do you control which X chromosome the RNA attaches to, and what happens if some RNA attaches to one X chromosome in one cell, but to the other X chromosome in another cell? Maybe this process is only unidirectional - you can always choose to have a girl, but still have to rely on random chance to have a boy.

      Also the article doesn’t make it sound like they let the fetuses actually develop- what happens if an organism- let’s call it an XY female, for clarity’s sake- goes through puberty? Would that organism have genitals of a phenotypical female but grow the secondary sex characteristics of a male? Could an XY female be fertile? If so, would she have fertility issues if half her gametes have Y chromosomes? What would even happen if a Y chromosome egg was attempted to be fertilized by a sperm?

      This is absolutely fascinating work, but we’re probably not at the “designer baby” stage quite yet.

      edit: A quick look at Quora seems to indicate that a YY fertilized egg would not be viable.

      • Dkarma@lemmy.world
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        6 months ago

        No we actually do. Eliminating the sry expression caused a sex organ reversal in pigs and mice.

      • NoIWontPickAName@kbin.earth
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        6 months ago

        So you can take an embryo that is in a uterus and change that embryos sex?

        I feel like that’s what they are talking about, not picking out of a cluster of them.

        I’m genuinely interested

        • GreyEyedGhost@lemmy.ca
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          6 months ago

          There has been gender selection for ivf for over a decade now. The sperm can be separated by X or Y and only one can be used to fertilize the eggs.

      • tal@lemmy.todayOP
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        6 months ago

        I don’t know enough about the state of genetic engineering to speak with much authority on the topic, but I don’t think that we today have a mechanism to modify the genes in all the cells of a many-celled organism.

        Like, I don’t think that this has practical applications as an alternative to hormone replacement therapy or something, if that’s what you’re saying; it’d be used at the single-cell stage, so that the changes propagate as the cells replicate and the organism grows.

        You could maybe create a younger, female clone of yourself, but I assume that that’s not what you’re after.

        • LibertyLizard@slrpnk.net
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          6 months ago

          Also, these changes wouldn’t necessarily change an adult body to a different sex even if you did reprogram every cell. It’s merely the step that determines the way the rest of development unfolds. But once that development happens, much of it is irreversible (at least within the human genome and its available tools).

          It might someday be possible to build a whole new package of genetic machinery to change a person’s sex completely but this is far beyond current technology since nothing like this exists in the human body or any animal remotely similar to humans. It would have to be created from scratch, while most genetic engineering today is more or less cutting and pasting from other organisms or breaking shit to see what happens (as in this research).

            • LibertyLizard@slrpnk.net
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              6 months ago

              A little but not as much was we would want. I was thinking about mentioning that but it’s in tadpoles as well so it’s not even clear a similar process could work for adults. Still, it’s a place to start the research.

          • tal@lemmy.todayOP
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            6 months ago

            Like, growing a female clone of parts of your body, and then implanting organs from it into your body? That’s creative. I dunno, good question.

            I don’t know whether immune rejection of cloned organs is an issue or not. I guess it’d be comparable to implanting an organ from an identical twin.

            kagis

            Sounds like that’s possible, at least in terms of immune response.

            https://www.verywellhealth.com/understanding-and-preventing-organ-transplant-rejection-4147557

            Isograft: This type of transplant is done between a genetically identical donor and a recipient, such as an identical twin. There is virtually no risk of rejection in this case, as the body does not recognize an identical twin’s organ as foreign.

            thinks

            I think that a problem you’d have with anything that has a lot of sensory input and output is that you’d have to regrow nerves. My understanding is that in cases of something like spinal cord damage, an issue is that scarring prevents nerves from reconnecting correctly – suppressing scar formation is something that had to happen when trying to deal with spinal cord issues. I’ve also got no idea what the constraints are on wiring things up correctly, but I imagine that there are some.

            kagis

            https://en.wikipedia.org/wiki/Nerve_injury

            Recovery of a nerve after surgical repair depends mainly on the age of patients. Younger the patients, better the prognosis, because of better healing capacity of young tissues. Young children can recover almost normal nerve function.[29] In contrast, a patient over 60 years old with a cut nerve in the hand would expect to recover only protective sensory function, that is, the ability to distinguish hot/cold or sharp/dull; recovery of motor function would be likely incomplete.

            So even with one’s own body parts, nerve regeneration apparently isn’t going to be perfect, but we can have some degree of it.

      • metaStatic@kbin.social
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        6 months ago

        I’m not against transhumanism, but if there isn’t an attainable goal you’re just getting stuck in the trans part. I’ll let you be the test pilot.