Announcement

Collapse
No announcement yet.

The male X chromosome

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by 1798 View Post
    I have examined the 500 snps of each of the 14 matches.
    Oh, OK. You can probably see that your X does not match anybody along the entire length. You must be seeing segments like you would on the autosomes then.

    Do you have multiple matches in the same place with other males? There are some men who match multiple men in the same place near the centromere and these regions don't crossover and break up very often.

    I have seen some interesting biogeographical patterns in some of the "kernels" that make up a match. So in that respect I think you are correct in asking why we don't follow the X back in time and mine for SNPs. I am one who actually believes in looking for these tiny phylogenetic trees even though these are hard to track because of mixing. In some regions on the X, it is productive.

    Some researchers use 100 SNP kernels to patch together a biogeographical prediction and can tell you in some cases where your ancestors came from getting it down to a local geographical area.

    We used to dissect out small sections from another company and compare raw data with each other in the old days when we did not have these chromosome browsers. It is still a great learning tool to do that to see the patterns. I don't know why we are not data-mining more markers and haplotypes from the X. Some people can't see the phylotrees for the forest. It is labor intensive so we really need computers to follow the migration paths of the nodal markers back in time. Maybe it is being done more than I realize.

    Comment


    • #17
      Originally posted by Kathy Johnston View Post
      Oh, OK. You can probably see that your X does not match anybody along the entire length. You must be seeing segments like you would on the autosomes then.

      Do you have multiple matches in the same place with other males? There are some men who match multiple men in the same place near the centromere and these regions don't crossover and break up very often.

      I have seen some interesting biogeographical patterns in some of the "kernels" that make up a match. So in that respect I think you are correct in asking why we don't follow the X back in time and mine for SNPs. I am one who actually believes in looking for these tiny phylogenetic trees even though these are hard to track because of mixing. In some regions on the X, it is productive.

      Some researchers use 100 SNP kernels to patch together a biogeographical prediction and can tell you in some cases where your ancestors came from getting it down to a local geographical area.

      We used to dissect out small sections from another company and compare raw data with each other in the old days when we did not have these chromosome browsers. It is still a great learning tool to do that to see the patterns. I don't know why we are not data-mining more markers and haplotypes from the X. Some people can't see the phylotrees for the forest. It is labor intensive so we really need computers to follow the migration paths of the nodal markers back in time. Maybe it is being done more than I realize.
      Thanks Kathy.I think in the future that the scientists will be able to trace some of the female lines through one X.I think that they will also be able to separate the 1-22 chromosome pairs and know which came from the male and female.
      The precision at birth that goes in to making a human is unbelievable.One or two minute mistakes can lead to serious health problems.

      Comment


      • #18
        Originally posted by 1798 View Post
        A woman is female because she has two X chromosomes so both are female.One of the Xs would be very hard to trace because it recombines but the other doesn't. So the females can trace one of their maternal lines through the so called "male" X.
        I have 14 X matches and I have examined the SNPs that we match and none of them have combined alleles like the 1-22 chromosomes.
        My question is why doesn't someone put together an X tree for this female line? Does that make sense?
        Originally posted by 1798 View Post
        I have 17,509 X SNPs from Family Finder.
        AA 24%
        GG 26%
        TT 24%
        CC 26%
        From what I have read these are only a small percentage of the whole X chromosome but you say that they were recombined before they were passed on to me.
        Female can't trace their maternal line through their X-Chromosome. Female got one X from her mother and one X from her father. X from her father will be (almost) identical with her father's X. But one X from her mother is recombination of 2 X that her mother had (one X from her maternal grandfather and one X from maternal grandmother).

        It doesn't mean the X she can trace her line through her X that she got from her father because her father got it from the paternal grandmother. The paternal grandmother has 2 X (from the mother of the paternal grandmother and the father of the paternal grandmother). And it already got recombined when it passed to the father. So the X-Chromosome just like autosomal, can detect multiply ancestry but can't point to paternal ancestry. Recombination is a random process. So we can't know which part will be pass to the next generation and which part will be vanish.

        Sorry, English is not my native language so I am afraid you are confuse to read my explanation. But at least I tried to explain.

        Comment


        • #19
          Paramesware: Yes, that is easy to understand and very helpful. Thank you.

          Comment


          • #20
            Originally posted by Parameswara View Post
            Female can't trace their maternal line through their X-Chromosome. Female got one X from her mother and one X from her father. X from her father will be (almost) identical with her father's X. But one X from her mother is recombination of 2 X that her mother had (one X from her maternal grandfather and one X from maternal grandmother).

            It doesn't mean the X she can trace her line through her X that she got from her father because her father got it from the paternal grandmother. The paternal grandmother has 2 X (from the mother of the paternal grandmother and the father of the paternal grandmother). And it already got recombined when it passed to the father. So the X-Chromosome just like autosomal, can detect multiply ancestry but can't point to paternal ancestry. Recombination is a random process. So we can't know which part will be pass to the next generation and which part will be vanish.

            Sorry, English is not my native language so I am afraid you are confuse to read my explanation. But at least I tried to explain.
            Everything is possible.
            Great mines discuss ideas.
            Average mines discuss events.
            Small mines discuss people.
            My English isn't great but you will understand I am Irish.

            Comment

            Working...
            X