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发帖数: 19713 | 1 Researchers Discover Sex-Change Gene
By Diane Anderson-Minshall
Dmrt1 XX XY CHROMOSOMES X390 (FAIR UNCREDITED) | ADVOCATE.COM
Researchers at the University of Minnesota Medical School and College of
Biological Sciences have discovered a gene that is required to maintain male
sex throughout life.
The research team, led by David Zarkower and Vivian Bardwell of the
University of Minnesota’s department of genetics, cell biology, and
development, found that removing an important male development gene, called
Dmrt1, causes male cells in mouse testes to become female cells. The
findings were published today in the online edition of Nature.
According to Medical Xpress, a Web-based medical and health news service,
the study determined that in mammals, sex chromosomes (XX in female, XY in
male) determine the future sex of the animal during embryonic development by
establishing whether the gonads will become testes or ovaries.
"Scientists have long assumed that once the sex determination decision is
made in the embryo, it's final," Zarkower said. "We have now discovered that
when Dmrt1 is lost in mouse testes — even in adults — many male cells
become female cells and the testes show signs of becoming more like ovaries."
Previous research has shown that removing a gene, called Foxl2, in ovaries
caused female cells to become male cells and the ovaries to become more like
testes. According to Zarkower, this latest research determines that the
gonads of both sexes must actively maintain the original sex determination
decision throughout the remainder of life.
This discovery is a breakthrough for genetic researchers and may have
implications for transgender and intersex individuals.
"This work shows that sex determination in mammals can be surprisingly prone
to change and must be actively maintained throughout an organism's lifetime
," said Susan Haynes, who oversees developmental biology grants at the
National Institute of General Medical Sciences of the National Institutes of
Health. "These new insights have important implications for our
understanding of how to reprogram cells to take on different identities and
may shed light on the origin of some human sex reversal disorders." |
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