Diabetes Can Damage Men's Sperm Posted: 05-26-07 12:40pm
An Irish study suggests diabetes can
damage DNA in men's sperm, thereby
affecting fertility.
In the first study to compare the
quality of DNA in sperm from diabetic and
non-diabetic men, researchers at Queen's
University in Belfast, Northern Ireland,
discovered DNA in the nuclei of the sperm
cells had greater levels of fragmentation
in diabetic men -- 52 percent versus 32
percent in non-diabetic men -- and that
there were more deletions of DNA in the
tiny, energy-generating structures in the
cells called mitochondria.
Ishola Agbaje, who led the study, said:
"If the increasing trend in the incidence
of type I diabetes continues, this will
result in a 50 percent increase over the
next 10 years. As a consequence, diabetes
will affect many more men prior to and
during their reproductive years."
Professor Sheena Lewis, scientific
director of the university's Reproductive
Medicine Research Group, cautioned it was
still unclear whether the DNA damage
caused by diabetes would have the same
effect on men's fertility and the health
of future children as DNA damage caused by
other factors, such as smoking.
The study is available online in the
journal Human Reproduction
Sperm Activates Egg By New Protein
Canadian researchers have discovered a new
protein involved in the fertilization of
an egg by sperm.
The discovery by Richard Oko and
colleagues at Queen's University in
Kingston, Ontario, might lead to new
reproductive technologies and better
understanding of reproductive disorders.
When the sperm head and egg start
fusing and create an opening between them,
the sperm cell releases proteins through
the opening that activate the egg, said
Oko.
That allows the sperm cell to further
enter the egg and mix its material with
that of the egg, thus creating one cell --
the zygote. The egg activation steps are
well known, but it is not yet clear which
molecules initiate the activation process.
The study identifies a protein that
appears to play a key role in the first
stages of egg activation. The researchers
isolated the protein, called postacrosomal
sheath WW domain-binding protein, or PAWP,
and found without PAWP, sperm cells were
