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From: "Dennis Garvey" <>
Subject: Re: [DNA] DYS 388 Mutation Rate?
Date: Wed, 27 Oct 2004 10:51:25 -0700


Ken wrote:

>But in the recent paper on haplogroup J and its subclades by DiGiacomo et
>al in Human Genetics 2004, they inferred some individual marker mutation
>rates from analyzing the found distributions of J haplotypes in Europe and
>Mideast and employing some simulation software (Batwing?). They concluded
>that DYS 388 had a higher mutation rate than other familar loci such as DYS
>392, 393, etc. I believe their estimated rate for DYS 388 was almost an
>order of magnitude greater than the McDonald value.

DYS388 is a trinucleotide STR - which means it has three "letters" (bases)
in its repeat unit.

Kayser et al found that trinucleotide YSTRs behaved differently than the
tetranucleotide markers (the majority of YSTRs are tetranucleotide - i.e.
they have four bases in the repeat unit). They saw that the trinucleotide
YSTRs either mutated very slowly or very fast. So they speculated that the
mutation rate may be affected by something other than just the number of
repeats. Their guess was that it may be influenced by the "absolute length"
of the YSTR. In that case, a trinucleotide YSTR with 10 repeats (30 bases
long) wouldn't mutate as quickly as a tetranucleotide YSTR with 10 repeats
(40 bases long).

So DYS388=12,13, or 14 (like for most haplogroups) may be in the "dead
slow" range of absolute lengths, while DYS388=15, 16, or 17 (seen in many
haplogroup J's) may put it over into the "very fast" mutating range of
absolute lengths.

Dennis Garvey
___________________________________________________________
Y-Chromosome Haplogroup Website

http://freepages.genealogy.rootsweb.com/~dgarvey/DNA/markers.htm
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