From: Damien Broderick (d.broderick@english.unimelb.edu.au)
Date: Fri Jan 11 2002 - 21:00:48 MST
At 02:28 PM 1/11/02 +0000, Fabio wrote:
>>We might actually be missing a lot of negative subtext simply by being
>>so happy about seeing "our" ideas expressed.
>
>You've got a point there... despite the program putting a very positive spin
>the potential of genetics (judging from the trailer, anyway...) I have
>already come across a disappointing comment in a UK newspaper, about the
>program: "fascinating and frightening..."
Last night I watched a BBC Horizon program, LIVING FOREVER, finally
broadcast two years late in Oz. Promos made it look very technophilic, and
in some respects it was. But despite some nice interviews with a few good
people like Dr Michael West, the narration
http://www.bbc.co.uk/science/horizon/living_forever_script.shtml
was full of errors, tiresome mumbo jumbo (`defying the laws of nature' blah
blah; funny how you don't hear that said any longer about wearing glasses
and catching a bus) and faux X-Files theme music. The material on telomeres
was highly misleading--our organs probably *don't* age because of telomere
degradation; hardly any chromosomes reach that point in vivo unless they
are in rapidly reproducing tumor cells or progeric kids. Lee Silver's
comments on evolution were misleading to the point of outright error. I
especially liked this typical idiocy:
>NARRATOR: So what would we gain by postponing death indefinitely?
[Me:] Uhh... I dunno... Uhhh... uhhh.... really, I just can't think of
*anything* to be said for not getting old and sick and then dying...
The only interesting element to me was a report on Dr Ellen Heber-Katz of
the Wistar Institute in Pennsylvania and her mutant regenerating mice which
I urled yesterday. Off to google to see why this hasn't become more famous
in the intervening two years or more since the program was made...
Ah, this from Nature in 1998:
http://www.nature.com/nsu/981008/981008-9.html
Understanding the genetic
differences in the MRL/MpJ mice is the first step.
The wound-healing ability is inherited, so when
Heber-Katz and her colleagues allowed MRL/MpJ
mice to breed with normal laboratory mice, the
offspring inherited some healer ability, but the
extent varied from individual to individual.
The fewer genes involved, the fewer distinct
groups of healer abilities should be seen in the
offspring. In fact, the amount of variety in the
offspring's healing powers suggested to the
researchers that there were at least four genes in
control. By measuring the extent to which the
offspring inherited the healing trait and by finding
'marker' genes that are inherited at the same time
(suggesting the genes are close together), the
researchers also managed to suggest where on the
various chromosomes the healer genes were.
They believe they have found gene locations on
chromosomes 8, 12 and 15, with two regions on
chromosome 13. There may even be another site
on chromosome 7 - so there seem to be a possible
six genes, rather than the predicted four. The
genes are all inherited from the MRL parent except
for one, which comes from the normal lab mice,
but is presumable masked in some way by its
other genes.
What these 'healer' genes are, what they do, and
how they are regulated, remains to be discovered,
but it is clear that regenerative healing is no simple
process. The genes may encode receptors, growth
factors, and signalling chemicals - one likely
candidate is a receptor for retinoic acid, a
chemical which is important during development
and skin growth.
But one extremely interesting finding is that the
candidate healer genes do not include any of the
genes that cause the autoimmune profile of
MRL/MpJ. Healing powers are not simply due to
diminishing immune system activity.
(C) Macmillan Magazines Ltd 1998 - NATURE NEWS
SERVICE
And she started this research in 1994, as reported in March 2001:
http://www.upenn.edu/gazette/0301/giresi.html
[she] now devotes about
80 percent of her time to mapping the
gene loci that confer these unique
regeneration properties and analyzing
their patterns of expression. She hopes
that her research on the “healer”
mouse—as it was coined at
Wistar—which exhibited full replacement
of its epidermis, dermis and cartilage in
three to four weeks following ear
puncture, could be a boon to burn
victims and might contribute to research
on stem cells, wound healing, and
cartilage and nerve regrowth. But that’s
still a long way off. For now, Heber-Katz
says, the leading question on her mind is,
“Why are these mice able to do this and
other mice are not?”
Good question!
Damien Boderick
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