[scotty79]

That can't be good. Life cycle of a human egg is organized around preserving mitochondria to be as young and fresh as possible across generations. Using adult cell, even a stem cell to make an egg probably gives it mitochondrial damage that usually takes hundreds of human generations to accumulate.

[Protostome]

Mitochondria can be translplanted/replaced. There already therapies and babies born out of these kinds of procedures

[scotty79]

Can you point me to anything about mitochondrial transplants? I'd love to see bat mitochondria transplanted into other mammals. They must have really superior ones given the energy expenditures needed to support flight and their long lifespans.

[Protostome]

I will let the experts continue from here :) This review is from 2020, i bet things have progressed since then

https://pmc.ncbi.nlm.nih.gov/articles/PMC7169912/

[scotty79]

It's not so much a mitochondrial transplant, as it is fertilized egg nucleus transplant. Not just mitochondria are used from the third donor but their whole egg (sans nucleus). So unless a human might develop from a bat egg just from swapping out nucleus, which I'm sure it's not the case, super-powered batman must remain a fantasy.

[Protostome]

Oh, so that's what you were aiming for, LOL

there are many reasons for this chimera not to be viable, mitochondria co-evolves with the nuclear DNA, you can't just take a mitochondria from a totally different species

[scotty79]

Bats are kinda close though. Maybe it would require just a handfuls specific adjustments to nuclear DNA, at most. Worth a shot if it could give us for example 2x multiplier for a healthy lifespan. Even getting 10 year old mice would be very cool.

[type0]

I don't, isn't this the recipe to get IRL Morbius?

[NoGravitas]

Or Man-Bat.

https://en.wikipedia.org/wiki/Man-Bat

[Schlagbohrer]

Batboy, real at last

[ACCount37]

If this ever becomes a pressing issue, you can do cell selection and mitochondrial transplants.

As long as mitochondrial damage is not uniform, you can sample for cells with low mtDNA damage and no known-harmful mutations, and base your eggs on those cell lines. Do "in vitro" what natural selection would have done "in vivo", reduce damage accumulation that way - potentially to zero.

And if you really want to, you can make eggs off a "known good mtDNA" cell line, then swap a new nucleus into them (cloning-like process), and get a cell line with target nuclear DNA and known good mtDNA. Mitochondrial replacement therapy. Then make eggs off that hybrid line.

Involved lab work, but, perfectly doable, and rides the same stack you already use for IVF. Mitochondrial replacement is already a known tech, but only worthwhile for cases of known harmful mtDNA anomalies currently. "Good mtDNA" eggs are sourced from donors instead of produced from cell lines currently, but this tech might change that too.

[khazhoux]

Instead of just dismissing this and saying this can't possibly work, it would be better to ask: how do they get around problems of mitochondrial damage, or have they not tackled that yet?

Because it is unlikely that you just punched a hole through the plan of the several dozen people in bioengineering, life sciences, and other related fields that are at this company.

[XorNot]

Or we could ask "what the hell are they talking about" and "can they cite even one single bit of useful peer reviewed evidence about this?"

Coz really that seems like the foundational problem here: claiming something rather crazy with obvious problems, like multigenerational mitochondrial damage in an organism which replicates literally billions of them just to be born.

[treyd]

I wonder if you could coax cells from the testes back into stem cells to then re-specialize into ovarian cells.

[Schlagbohrer]

Reverse Cremaster cycle?

[fellowmartian]

Life wouldn’t be here if mitochondria only accumulated damage. We can do in the lab what biology does in the wild - introduce selection pressures. Either by sequencing iPSC clones and picking the best, somehow inducing the natural purifying selection, or simply using a donor mitochondria.

[rf15]

genuinely curious: how does any life still exist if this holds true?

[jmcgough]

I think they're arguing that a somatic cell from an older human contains mitochondria that's more degraded. Egg cells are all created before birth, and each is pre-seeded with a large number of mitochondria.

[scotty79]

When the damage accumulates across generations the natural selection has opportunity to weed out particularly harmful instances. You can get a feeling for how important avoiding the mitochondrial damage is and how hard it is to mitigate, by looking at how fiercely the reproductive process protects them from aging.

[someonebaggy]

And with this you get a hundred times the damage (mutation) but still only the same amount of selection.

[Jackobrien]

Really interesting point if true. Makes sense to me, and I’m sure the team is trying to solve it