Researchers at Shanghai's Fudan University announced the
discovery of the world's first genetic link for human infertility.
This breakthrough came when studying the movement of the SUN1
protein contained in the nuclear membrane of mice cells since 2003.
When the protein was broken down, the disruption halted the usual
pairing and recombination of chromosomes during the reproduction
process among sexual cells.
Mice thus born with a broken SUN1 protein had markedly smaller
testes and ovaries than normal mice which impaired the production
of sperm or eggs, explained researchers.
"We can infer that the SUN1 protein plays a key bridging role in
the reproductive process of mice, which also provides a target
point for the diagnosis of human infertility," said Ding Xu, a PhD
researcher at the institute and the article's lead writer.
Scientists uncovered the pairing and recombination process of
chromosomes long ago, although light had so far not been shed on
the process' initiating factor.
"A genetic reason for most infertility has been ambiguous for a
long time," said Xu Ren'er, an associate professor and co-author of
the article.
Ten percent to 15 percent of the world's couples suffer
infertility problems and worsening environmental pollution, among
other factors, may drive this number upwards.
As mice and humans share about 99 percent of reproduction genes,
"the finding is expected to provide a new clue for human beings to
understand the reason for the disorder," Xu said.
However, he sought to quell any enthusiasm by saying this
finding was still a long way off from being applied to treating
human infertility.
The breakthrough was published in Developmental Cell, a
leading international biology journal, on Monday and is set to be
reproduced in the respected academic journal Science on
Friday.
(Shanghai Daily June 6, 2007)