Re: Epigenetics - Something New!

On Sun, 4 Jul 2004 14:45:58 -0400 "Dick Fischer"
<dickfischer@earthlink.net> writes:
<snip>
If agouti mice are any indication, the answer could be yes. The
multicolored rodents make for a fascinating epigenetics story, which
Randy Jirtle and Robert Waterland of Duke University told last summer in
a Molecular and Cell Biology paper; many of the scientists interviewed
for this article still laud and refer to that paper as one of the most
exciting recent findings in the field. The Duke researchers showed that
diet can dramatically alter heritable phenotypic change in agouti mice,
not by changing DNA sequence but by changing the DNA methylation pattern
of the mouse genome. "This is going to be just massive," Jirtle says,
"because this is where environment interfaces with genomics."

Dust off your biography on J. B. Lamarck, he may be coming back into
fashion.

Oh no ... "Lamarck on Trial Too" by Phil Johnson? Egad!

Dick,
You need to read up on Lamarkianism, 'cause this ain't it. Lamark
believed that permanent directional inheritable change occurred as a
result of persistent activity. Methylation pattern is something that does
not change the genetics, just the phenotype so long as the methylation
remains. It may be shifted at any subsequent generation. Indeed, if I
recall the information correctly, some genes are inactivated by
methylation when they come from the male parent, but only for the
immediate offspring. It certainly is not permanent directional
inheritable change. Indeed, what is reported can be accomplished, to the
extent that genes are turned off, by those bits of DNA called SNPs.
Dave
Received on Sun Jul 4 23:12:28 2004