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Archiver > GENEALOGY-DNA > 2007-10 > 1191268461


From: Gabriela Novak <>
Subject: Re: [DNA] Y-DNA and Cloning
Date: Mon, 1 Oct 2007 15:54:21 -0400
References: <5338DF062085554AAEDD3DC9C7CACA920F7D46@ivey3.jlivey.com><42075AEA-1845-46CB-A12D-E19277447270@utoronto.ca><p06200704c326eb8704da@[10.0.1.200]>
In-Reply-To: <p06200704c326eb8704da@[10.0.1.200]>


True, but this procedure would be very risky in humans. In humans,
the DNA contributed by sperm and by an egg is marked (methylated),
one set is marked as maternal and one as paternal. This is called
imprinting. If you take a differentiated cell, it will have this
methylation already erased. If this happens by accident and the DNA
from either the mother or father is improperly labelled, for example,
if the paternal DNA is also labelled as maternal, serious disease
ensues. An example of improper imprinting is Prader-Willi syndrome
and Angelman syndrome. It will be tough to find a way to mimic
imprinting. Besides, I fail to see the advantages of cloning in
humans. The strength of species to survive is in variation, not
homogeneity.
There is, however, a procedure that could result in different mtDNA
being present than the mother's. A nucleus from a fertilized egg can
be transferred to another fertilized egg, from which a nucleus was
removed. I am not sure if this is being done, but it is possible. It
may increase the survival rate of older cells (from older mothers) if
the nucleus is transferred into a younger egg. However, I am
venturing out of my knowledge area, so I won't expand on that.
Gabriela

On 1-Oct-07, at 2:27 PM, Elizabeth Harris wrote:

>> cloning = generating twins
>>
>> not only would the Ys be the same, but the rest of the genome as
>> well.
>
>
> However, if the clone is produced by transplanting the nucleus of the
> donor cell into a recipient egg (the mechanism by which Dolly the
> sheep was cloned), the mitochondrial DNA of the resulting child would
> be that carried by the egg, not by the person being cloned.
>
>
> --
> Elizabeth Harris
>
>
> Personal genealogy webpage: http://www.duke.edu/web/chlamy
> Winston-Salem NC area genealogy: http://www.fmoran.com/
> HOLDER DNA project: http://www.mindspring.com/~holderdna/
>
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