In article <Pine.3.05.9504171453.C8530-b100000 at mcz>, dmw at MCZ.HARVARD.EDU (Daniel Weinreich) writes:
|> This morning I asked how many rounds of DNA replication per generation
|> occur in mammalian germ lines. I further speculated that if the Y-linked
|> clock runs faster it must be the case that male germline cells undergo
|> more rounds of DNA replication per generation than do female germline
|> cells.
|>|> An authority on precisely the question of Y-linked mammalian clock rates,
|> who cites several references regarding the number germline DNA replication
|> per generation in mammals kindly writes as follows:
|>|> >From GSBS005%UTSPH.THENET at lib.tmc.edu Mon Apr 17 13:58:34 1995
|> >Date: Mon, 17 Apr 95 12:48:13 CDT
|> >From: GSBS005%UTSPH.THENET at lib.tmc.edu|> >To: dmw at mcz|> >
|> >My colleagues and I have published some data on these issues.
|> >The references can be found in the following papers and the references
|> >therein: Shimmin et al. Nature 362, 745, 1993; Chang et al. PNAS 91, 827,
|> >1994; and Chang and Li, J. Mol. Evol. 40, 70, 1995.
|> >Best regards, Wen-Hsiung Li
|>|> Happy reading everyone, and thank you Dr. Li.
There is another explanation for the observed discrepancy in these
papers: DNA in sperm is methylated, while in ova it is not. This
would mean that genes on the Y chromosome would experience more
C to T transitions independently of any effect that may be caused
by cell division.
Ingrid
**************************************
Ingrid Jakobsen at anu.edu.au
Human Genetics Group
John Curtin School of Medical Research
Australian National University.
P.O. Box 334 Canberra, ACT 2601
