
Male DNA Commonly Found in Women’s Brains - daegloe
http://www.sciencedaily.com/releases/2012/09/120926213103.htm
======
alexholehouse
This story already made the rounds on wednesday
<http://news.ycombinator.com/item?id=4582655>

I'm yet to read the paper, but the comment highlighted in the thread from
Wednesday raises some points[1]. For ease of access I'll re-replicate it here;

 _"This is just a PCR study. No evidence that the foreign human DNA even
entered host cells, much less that it was expressed. Probably shows only that
minute quantities of foreign human DNA can hang around a host body for a
while. Most likely explanation is that it gets bound up in the extracellular
matrix. Being that the DNA is of human origin, it would not trigger an immune
response, but rather, it would just be slowly degraded like the host's own DNA
when it is released from dead cells (part of the normal, perpetual turnover of
cells). DNA is hardy stuff; people have sequenced DNA from Neanderthal bones.
Study co-author J. Lee Nelson's comments are ridiculous hype. He should be
ashamed of himself. That those comments were published in this newspaper
uncritically is also an embarrassment. This work was published in PLoS ONE.
PLoS ONE articles are peer reviewed only for the validity of the methods used,
not for the importance of the subject matter or the validity of the
conclusions drawn. This is where you can publish all sorts of meaningless
crap."_

I disagree with the extremity of the commentor's view on PLoS ONE articles,
and feel they should perhaps have noticed that Dr. Nelson is a lady, not a
dude, but still something worth considering.

[1] - [http://www.latimes.com/health/boostershots/la-heb-women-
brai...](http://www.latimes.com/health/boostershots/la-heb-women-brain-
microchimerism-20120926,0,6446716.story) , comment 2

~~~
001sky
Original paper has also been posted here, for those interested.

<http://news.ycombinator.com/item?id=4582700>

 _Male Microchimerism in the Human Female Brain_

------
lkrubner
Considering that everyone of us, without exception, gets 50% of our DNA from
our father, the phrase "male DNA" deserves some definition. One assumes that
perhaps they are talking about DNA that is normally only found on the g
Y-chromosome, but they don't say that, and in this case, that is an
unfortunate oversight. A science publication should not leave readers guessing
about what exactly is being discussed.

They do use the phrase "male cells of fetal origin" but they don't explain why
these are male cells. There are several possible explanations, and I am
curious which one is true here. Again, they could be talking about a type of
expression that relates to Y chromosome. But there was last year the
interesting study that suggested end-stage cells know their sex through a
process we do not yet fully understand. So what is this study actually saying?
I wish they had clarified what "male DNA" means in this context.

~~~
GregBuchholz
At the bottom of the article, there is a link to the original paper:

[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045592)

...which can be downloaded (i.e. not behind a pay-wall). From the abstract:

"In this study, we quantified male DNA in the human female brain as a marker
for microchimerism of fetal origin (i.e. acquisition of male DNA by a woman
while bearing a male fetus). Targeting the Y-chromosome-specific DYS14 gene,
we performed real-time quantitative PCR in autopsied brain from women without
clinical or pathologic evidence of neurologic disease (n = 26), or women who
had Alzheimer’s disease (n = 33). We report that 63% of the females (37 of 59)
tested harbored male microchimerism in the brain."

------
brianpan
Similar earlier stories:

Fetus donates stem cells to heal mother's heart:
[http://www.newscientist.com/article/dn21185-fetus-donates-
st...](http://www.newscientist.com/article/dn21185-fetus-donates-stem-cells-
to-heal-mothers-heart.html)

Baby/mother cell exchange: <http://kottke.org/12/01/babymother-cell-exchange>

------
EGreg
I wonder if mothers also similarly have DNA from female babies, but we just
haven't detected it yet because it was easier to distinguish the male DNA.

