ONLINE Courses
Structure
of the Universe
Chaos
& Fractals
July 20th, 2004
Munch and
Learn
Experimental Genetics and
Aging
Professor
David Burke (UM Human Genetics Dept)
For those who
couldn't make the lecture,
here is a pdf file of the
lecture slides.
If this file is too
large for downloading, here is a
compressed version of the same slides
to download and
view.
Dave
Burke
Math Auditorium, 1360 East
Hall
-- Notice Change of Venue! --
6:30-7:30pm
What is this?? See below!
Link is to Burke lab which
studies the genetics of aging.
Abstract: As a mammal develops, certain genes are turned on and off. The pattern of those genes available to be used in a cell at any time is the epigenetic information of the cell. This is what determines the type and function of the given cell, and is inherited by the daughter cell from the mother cell in cell reproduction. However, this inheritance may not be as accurate, or stable, as the inheritance of DNA sequence information. Could a long term loss of epigenetic fidelity, or otherwise put, a rise of epigenetic noise, be a possible molecular genetic mechanism for aging?
To test this, the Burke lab studied the mosaic of silenced X-chromosomes in mice. Every female has two X-chromosomes, one maternal and one paternal. (Every male has only a maternal X-chromosome.) Early in the development of a female, each cell chooses, independently of one another and at random, one of the two X-chromosomes to be silenced, a good example of epigenetic information! After cell division, this gives rise to patches of genes from one or the other of the maternal or paternal X-chromosomes. The picture above shows two mice, female left and male right, under a fluorescence microscope: a test gene on the X-chromosome has been made to flouresce. The female shows the mosaic effect because of the two different types of X-chromosomes (she has inherited the ``glowing" gene from her mother, but a non-glowing alternative from her father), while the male has only one type, which is why he glows everywhere at the same rate.
Using this pattern of X-silencing, the Burke lab was
able to measure the loss of silencing over time in female mice. The
rate is small, but much larger than the loss of DNA information over
time. Thus, while DNA information loss is too small to account for the
function loss seen in aging, loss of epigenetic information is large
enough to play a significant role in the aging process!
More about aging research at UM from
the popular press:
Yoda, the world's oldest
mouse, celebrated
his fourth birthday on Saturday,
April 10, 2004 .
A dwarf mouse, Yoda lives
in quiet seclusion
with his cage mate, Princess
Leia, in a
pathogen-free rest home for geriatric
mice
Update: On
April 22, Yoda died peacefully
in his cage
at the U-M Medical School.
He was four
years and 12 days old!
Ice Cream Party afterwards
in Math
Atrium!
Lecture: 6:30 - 7:30, 1360 East Hall
Ice Cream: 7:30 - 8:30, Math Atrium
MMSS Public Invited!
(Parents, UM Community,
etc.)
Comments or suggestions? Write to the
MMSS Program Coordinator .
Back to the MMSS home page .
Michigan
Math & Science Scholars Program
Department of Mathematics
525 E. University; 2082 East Hall
Ann Arbor, MI 48109-1109
mmss@umich.edu
(734) 647-4466
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