08-08-2000
By Susan Linnee Associated Press Writer Sunday, July 16, 2000; 12:02 p.m. EDT NAIROBI, Kenya --
Nibbling away in boxes filled with wood chips in a building overlooking the
Ngong Hills, thousands of Kenyan mice are ready for the most important job of
their
lives. Now that scientists and researchers have mapped about 97
percent
of the human genome, they will need a guide to help them navigate the
secrets of the genes. The Nairobi rodents, they hope, will be
their
Virgils. The genomes of mice and humans are 80 percent identical;
they
have virtually identical sets of genes, but the sequences differ
slightly.
A comparative study of mouse genes will help explain the significance of
the string of 3 billion genetic letters uncovered in the milestone
sequencing of human DNA announced in June in Washington. "The
human
genome sequence stops here. To find the function of the (human) genes,
here actually comes the mouse," said Fuad Iraqi, molecular
geneticist and
gene mapper extraordinaire. In order to determine the function of
human
genes, researchers can remove parallel genes from so-called
"knock-out
mice," that often reveal by their subsequent defects the natural
functions
of the genes they lack. Iraqi, a 39-year-old Arab-Israeli, runs
the mouse
project at the International Livestock Research Institute on the
outskirts
of the Kenyan capital. He is one of group of 400 to 500 mouse
specialists
around the world who meet every so often to compare notes. This
year at
their meeting in Philadelphia the project to map the mouse genome was
officially launched. With about 97 percent of the human genome
sequenced,
the equipment and resources involved in that endeavor are now being
dedicated to the mouse, only the fourth living organism to be
genetically
mapped. The other two are the roundworm and the fruit fly. The
mouse
community will meet again in November in Narita, Japan, to assess
progress. Scientists have been using mice in research since 1664
when
English physicist Robert Hooke first observed the reaction of the
rodents
in his experiments on the properties of air. In its April 14
issue,
Science magazine devoted 10 pages to what it called "biomedicine's
model
mammal," detailing the rise of the international mouse trade and
citing
forecasters who say mouse use could grow by 10 to 20 percent annually
over
the next decade. What makes the ILRI mice so interesting to
researchers
is that they represent 13 generations of crossbred strains that can be
used for studying genes underlying traits like lung cancer, malaria and
obesity - all of interest to human beings and pharmaceutical companies.
The average research mouse population is inbred and does not offer such
a
broad genetic spectrum to choose from. "This is the only
mouse population
that exists today to find genes in the mouse related to human
genes,"
Iraqi said, holding a wriggling brown mouse by its tail. Stephen
Kemp,
professor of molecular genetics at the University of Liverpool in
England,
said the crosses of the ILRI mice were originally established using
lines
which differed in their resistance to sleeping sickness, "and they
have
already provided very fine localization of the genes involved in this
important disease." Because the same lines of mice differ in
other ways
and have different susceptibilities to many diseases and parasites as
well
as some important behavioral differences (including a predilection for
alcohol), Kemp said the ILRI advanced lines "represent an important
resource for scientists wishing to isolate the genes involved in all of
these traits." ILRI's original interest in mice arose from
its mission to
use biotechnology to improve livestock productivity in developing
countries, particularly within the small-holder sector. A part of
an
international consortium of agriculture and livestock research
institutes
in developing countries, ILRI is funded through the Consultative Group
on
International Agricultural Research. Iraqi and Tanzanian colleague
Onesmo
ole-MoiYoi, a molecular biologist, have both used the mice in their
research to map and clone mouse genes associated with parasitic diseases
that affect cattle in Africa. Iraqi's department is currently
conducting
mouse-based gene research for several U.S. institutions on lung cancer,
obesity and the genetic origins of certain human behavioral traits.
He
said scientists had been aware of the value of the mouse in genetic
research since the early 1980s, but they lacked the tools and resources
to
exploit them. Since 1995, the introduction of automated
gene-sequencing
machines (ILRI has four; Celera Genomics Group, the private firm
involved
in the mapping of the human and the mouse genomes, has 300) as well as
the creation of the specialized mouse population at ILRI have sped up the
process and changed everything. Most of the basic mouse research
at ILRI
is carried out by a laboratory staff of several hundred Kenyans,
something
that pleases Iraqi enormously. "When I travel and tell people
I work in
Kenya, they think we're doing science in the bush. They can't imagine
that
we have highly trained staff and state-of-the-art laboratories. It
doesn't
fit in with their Discovery Channel vision of Africa," he said.
"Actually, with these mice and these people, the South is showing
that it
has the potential to assist the North." © Copyright 2000 The
Associated
Press
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Article forwarded by:
Phelix A.O. Majiwa, Ph.D.
International Livestock Research Institute
Box 30709, Naivasha Road
Nairobi, Kenya
tel - 254-2-630743 fax - 254-2-631499
Via USA tel: 1- 650-833-6660 fax 1-650-833-6661
email: p.majiwa@cgiar.org
http://www.cgiar.org/ilri
