X gene transmission question

Voyager

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Some scientists used X -Chr to determine the sex type of the IE invasion 4500 BP. From these X-CHr analysis Some of them concluded that the IE was a male massive invasion. for example.
http://biorxiv.org/content/early/2016/09/30/078360
The starting point is that the X-Chr gene has 1/3 male origin and 2/3 female origin.
Why the male,female contributions to X-Chromosome is 1/3 2/3?
I would have say 1/4, 3/4.
because
if it's the case of a boy it's 100% female contribution,
0% male contribution
if it 's a girl It's 50% male contribution, 50% female contribution
then for any X chromosome the global contribution, since it's half chance to have a boy or half chance to have a girl, is :
for the total male contribution 1/2*50% + 1/2*0% =1/4
for the total female contribution 1/2*50% + 1/2*100%=3/4
 
Does that mean that X Chromosome, like Y Chromosome, doesn't combine one strand from mother and one strand from father, and is transferred as a whole piece from parents to a child?
 
I'm no expert on the X, but my understanding is that when a mother passes along an X chromosome to her children both male and female it is a "new" X chromosome, which is the product of recombination between her two X chromosomes. Thus the X a brother and sister receive from their mother won't be identical. This recombination is important because mistakes are corrected.

The father passes along the X passed to him by his mother, with no further recombination, but of course his mother's X was the product of recombination itself, from both her male and female lines.

So, as a female, I am getting the most "matches" on X genetic material from my paternal grandmother, which makes me happy as she was intelligent and tough.

What is not getting passed down in this scenario is the father's, father's X ancestry if I understand it correctly. So, as a female, I don't have any X inheritance from my paternal grandfather's X ancestry. That's also good. I didn't much like him.

As a male, you only get your mother's X ancestry, but from both the paternal and maternal lines. You get none of your father's X ancestry.

I think that's how it works.

This is a fun article on the subject on why daughters and fathers share such a bond:
https://www.psychologytoday.com/blo...loned-brains-the-secret-fathers-and-daughters

"I pointed out that the evidence is that, thanks to a large number of genes on the X being implicated in intelligence and related cognitive skills, you could say that you inherit your IQ from your mother. This is obviously the case with sons, who receive their one and only X-chromosome from their mothers (with a corresponding Y from their fathers). But it is indirectly true of daughters too, because although they get an X-chromosome from both parents, the X they get from their father is exactly the same one that he got from his mother—his daughter’s paternal grandmother. This makes daughters’ relatedness to their fathers in this respect different to their relatedness to their mothers. The X-chromosome a woman inherits from her mother is a random mix of genes from both of her mother’s Xs, and so does not correspond as a whole with either of them in the way in which her paternal X-chromosome corresponds to her father’s X."

It gets more complicated because genes might be disproportionately expressed in the body, but this is what he concludes:
"
This in turn means that some daughters might be cognitively much more like their fathers than their mothers—especially if the paternal X were disproportionately expressed in their brains. They would be X-chromosome clones of their fathers in this respect because each and every X-gene he had would be inherited and expressed by them. In other words, if sex chromosome expression is skewed in favour of the father’s X in the brain, a woman’s mind could end up surprisingly similar to her father’s in many respects—and, by the same reasoning, surprisingly dissimilar to her mother’s!"

This couldn't be more true in my case, but that's one anecdotal case. You'd need to do really well conducted studies to find out if this is generally true.

X chromosome inheritance for a female:
image042.jpg


X chromosome inheritance for a male:
X-Chromosome+fan+chart+male+-+from+Blaine+300dpi.tif


Don't take these as gospel; it's just what people have put up on the internet
 
I'm no expert on the X, but my understanding is that when a mother passes along an X chromosome to her children both male and female it is a "new" X chromosome, which is the product of recombination between her two X chromosomes. Thus the X a brother and sister receive from their mother won't be identical. This recombination is important because mistakes are corrected.

The father passes along the X passed to him by his mother, with no further recombination, but of course his mother's X was the product of recombination itself, from both her male and female lines.

So, as a female, I am getting the most "matches" on X genetic material from my paternal grandmother, which makes me happy as she was intelligent and tough.

What is not getting passed down in this scenario is the father's, father's X ancestry if I understand it correctly. So, as a female, I don't have any X inheritance from my paternal grandfather's X ancestry. That's also good. I didn't much like him.

As a male, you only get your mother's X ancestry, but from both the paternal and maternal lines. You get none of your father's X ancestry.

I think that's how it works.

This is a fun article on the subject on why daughters and fathers share such a bond:
https://www.psychologytoday.com/blo...loned-brains-the-secret-fathers-and-daughters

"I pointed out that the evidence is that, thanks to a large number of genes on the X being implicated in intelligence and related cognitive skills, you could say that you inherit your IQ from your mother. This is obviously the case with sons, who receive their one and only X-chromosome from their mothers (with a corresponding Y from their fathers). But it is indirectly true of daughters too, because although they get an X-chromosome from both parents, the X they get from their father is exactly the same one that he got from his mother—his daughter’s paternal grandmother. This makes daughters’ relatedness to their fathers in this respect different to their relatedness to their mothers. The X-chromosome a woman inherits from her mother is a random mix of genes from both of her mother’s Xs, and so does not correspond as a whole with either of them in the way in which her paternal X-chromosome corresponds to her father’s X."

It gets more complicated because genes might be disproportionately expressed in the body, but this is what he concludes:
"
This in turn means that some daughters might be cognitively much more like their fathers than their mothers—especially if the paternal X were disproportionately expressed in their brains. They would be X-chromosome clones of their fathers in this respect because each and every X-gene he had would be inherited and expressed by them. In other words, if sex chromosome expression is skewed in favour of the father’s X in the brain, a woman’s mind could end up surprisingly similar to her father’s in many respects—and, by the same reasoning, surprisingly dissimilar to her mother’s!"

This couldn't be more true in my case, but that's one anecdotal case. You'd need to do really well conducted studies to find out if this is generally true.

X chromosome inheritance for a female:
image042.jpg


X chromosome inheritance for a male:
X-Chromosome+fan+chart+male+-+from+Blaine+300dpi.tif


Don't take these as gospel; it's just what people have put up on the internet

http://www.eupedia.com/forum/thread...-and-behaviour?p=490491&viewfull=1#post490491
 
Did I understand right? Mother X and father X recombine when transfers to daughters. Mother X transfers as whole piece to sons.
 
Did I understand right? Mother X and father X recombine when transfers to daughters. Mother X transfers as whole piece to sons.

No, that's not it,particularly not the last piece, which I think is actually the opposite.

The X the mother passes on to each child, male or female, is almost always* a unique mix of the X dna from both of her Xs, the one from her maternal line and the one from her paternal line. The X that passes unchanged is the X a father passes on to his daughter. There can't be any recombination of X material on his side because he has only one X. However, that X isn't identical to his mother's, because recombination had taken place in her body when the egg was formed.

I'll take myself as an example. I got one X from my mother. It's a combination of data from her two Xs, one from her father and one from her mother. (it's not necessarily 50/50) I also got one X from my father, which is virtually unchanged from the X he received from his mother.

My brother didn't get any X material from our father's side because he got a Y instead. He got an X from our mother, which is a combination again of the data on her two Xs. It will be unique, not necessarily the same as mine, although there will be a lot of overlap.

This graphic is pretty good.

x chromosome inheritance.jpg

The asterisk is because in about 3% of cases, there's no recombination of the X and one passes down unchanged from the mother. No one seems to know why, but it seems to run in families.

If anyone thinks this is wrong, please correct the record.
 
I see. X is a tricky chromosome, lol.
 
You explained it all right, Angela. I would had just one more thing.


As we see on the female chart, the X-DNA ancestors don't have an equal contribution. After 7 generations, the line zigzagging between male and female contribute about 1/16th of a woman's X, while the all female line only 1/128th. Which makes the X chromosome very tricky to work with in genetic genealogy or ancient population affiliation.
 
Did I understand right? Mother X and father X recombine when transfers to daughters. Mother X transfers as whole piece to sons.
I think it's more like that.
YX0 of the father give either Y or X0 Y from his father X0 from his mother
X1X2 of the mother give a mixed X12 between X1 from her father and X2 from her mother
then
If it's a son he receives Y from his father and X12 from his mother: Y-X12

if it's a daughter she receives X0 from her father and X12 from her mother: X0-X12
 
Last edited:
Can X-Matches in gedmatch show me a path to my possible mtdna haplogorup, or is that impossible?
 

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