
Mitochondrial DNA can be inherited from fathers, not just mothers - pseudolus
https://www.nature.com/articles/d41586-019-00093-1
======
fanzhang
Summary: In 3 cases, Mitochondrial DNA from the father has been passed on to
the child.

Maybe this happens a lot more often than documented. In this case, it can
throw the field of mtDNA testing and implications into question.

Conversely, maybe it happens extremely rarely and only in pathological cases
(in the mathematics/statistics sense, if not the medical sense). In this case,
it's just a medical curiosity and only important insofar as a doctor treating
a patient with a rare disease may want to consider the _remote possibility_ of
this.

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ggm
It wasn't entirely clear how strongly this would invalidate conclusions drawn
from a belief it was matrilinial descent only. For instance, is this enough to
totally wreck the single-eve hypothesis? Or, change some of the patterns of
human dispersion models? Or the neanderthal-sapiens crossbreeding?

~~~
waserwill
Invalidating conclusions: not particularly; these results suggest that under
rare circumstances (in a few sorts of mitochondrial disease), mitochondria can
be transmitted paternally. It makes the matrilineal model slightly less
definitive, but, overwhelming often, accurate (note that people with
mitochondrial diseases rarely exhibit this feature, and are less likely to
reproduce anyway due to the disease).

Single Eve: still holds; given the small population size of humans in the
past, at some point there was a female ancestral to us all, as other lineages
would have stochastically died out.

Human dispersal and Neanderthal-modern human crosses: both have been examined
via autosomal DNA. Reconstructions of dispersal may be skewed in the following
manner: since we use X- Y- and mtDNA to look as sex ratios of admixture events
(such as in modern Caribbean populations, where there is more European male
influence and African/Native American female contribution), our reconstruction
may be skewed by these selection due to incompatibilities. We expect there to
have been some incompatibilities between modern humans and
Neanderthals/Denisovans—no doubt some were mitochondrial. But autosomal DNA
bears the evidence of our admixture. Likely some lineages (including those
with prehistoric-human mt- and Y-DNA) were lost, either due to selection,
stochasticity, or likely, both.

~~~
Cacti
Doesn’t the paper specifically say that they really have no idea of the impact
because not enough attention has been paid to determine the amount of paternal
inheritance? You sound awfully sure of yourself considering maternal
inheritance of mtDNA has been practically gospel for 50 years.

~~~
eftychis
I agree. I wouldn't rush to draw any conclusions, as this paper changes the
status quo. We can not say anything about the rarity of transmission events in
the past really. This work is focused particularly on heteroplasmy -- it
doesn't rule out other causes.

It does not seem we understand the mitochondrial inheritance mechanism during
conception.

~~~
samatman
We can set an upper bound on paternal mitochondrial inheritance: there are
hundreds of thousands of mitochondria in an egg, and tens in a sperm.

If all paternal mitochondria were transferred every time (unlikely‡), then a
child's mitochondria would be ~99.99% inherited through the mother.

‡ Unlikely because sperm mitochondria are located toward the flagellum in
order to power locomotion, and the capsule at the head is normally the only
part which fully penetrates the cell membrane.

Ref: [https://www.quora.com/How-many-mitochondria-are-there-in-
hum...](https://www.quora.com/How-many-mitochondria-are-there-in-human-cells)

~~~
belorn
Does that not assume that the mitochondrial from both parents are treated
equally in terms of inheritance? It seems to me that biological systems do not
tend to use random chance most of the times if there is a evolutionary
benefit, thus if there is such benefit I would predict that those "tens" would
be treated differently from those hundreds of thousands.

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geuis
I'm curious about how often this happens across different species. Once we
know that rate for mammals and/or specific species, for example, I wonder what
effect(s) it would have on estimations of generations and evolution over time.
Think about mitochondrial Eve for example.

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merricksb
Same source article as discussed here 2 months ago:

[https://news.ycombinator.com/item?id=18559212](https://news.ycombinator.com/item?id=18559212)

(Ars Technica article points to same PNAS article as this Nature article
does).

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peter_retief
I wonder if this will affect mapping for ancestry?

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dmazin
Can’t help but wonder if pointing out that mitochondria is the “powerhouse of
the cell” is in reference to the meme.

~~~
zik
The meme is in reference to this popular quote, not the other way around. The
quote has been around since Philip Siekevitz published an article on this in
1957.

~~~
__jahh
the quote is a meme that is submemes of the meme and the quote as "quote" and
not as saying

