the times | Saturday August 1 2020 2GM 19
News
The centuries-old view of how sperm
swim has been shattered by a break-
through in fertility science.
For 350 years, since the invention of
the microscope, it has widely been
assumed that sperm make their epic
voyage through the female reproduc-
tive tract by lashing their tails from side
to side, rather like eels.
Now scientists have revealed that
another animal analogy is more apt:
sperm, they say, are more like “playful
otters corkscrewing through water”.
The discovery was made possible by
state-of-the-art 3D microscopy, ultra-
high speed photography and mathe-
matics. These have combined to reveal
that the sperm tail is, in fact, wonky and
wiggles on only one side.
This uneven stroke puts the sperm at
risk of swimming in circles, which is
avoided through a clever adaptation.
“Human sperm figured out if they
roll as they swim, much like playful
otters corkscrewing through water,
their one-sided stroke would average
itself out, and they would swim for-
Sperm get wriggle on by swimming like playful otters
Rhys Blakely Science Correspondent wards,” Dr Hermes Gadêlha, head of
the Polymaths Laboratory at the Uni-
versity of Bristol’s department of engi-
neering mathematics, said.
Sperm’s rapid and highly synchro-
nised spinning causes an illusion when
viewed from above with traditional 2D
microscopes.
Under these conditions, the tail
appears to have a symmetric side-to-
side movement. The illusion caught out
Antonie van Leeuwenhoek, the Dutch
scientist who first observed sperm
through a microscope in 1678. He
described them as lashing their tails
from side to side, swimming “like eels in
water”.
The otter-like spinning of human
sperm is complex. The sperm head
spins at the same time as the tail rotates
around the swimming direction.
“Our discovery shows sperm have
developed a swimming technique to
compensate for their lopsidedness and
in doing so have ingeniously solved a
mathematical puzzle at a microscopic
scale: by creating symmetry out of
asymmetry,” Dr Gabriel Corkidi, of the
National Autonomous University of
Mexico, co-author of a study published
in the journal Science Advances, said.
Computer-assisted semen analysis
systems in use today, in clinics and for
research, still rely on 2D views to
observe the movement of sperm.
Therefore like Van Leeuwenhoek’s first
microscope they are still prone to this
illusion of symmetry while assessing
semen quality.
The new study, using 3D microscope,
potentially offers a new method of i-
nvestigating human fertility.
“With over half of infertility caused
by male factors, understanding the
human sperm tail is fundamental to
developing future diagnostic tools toidentify unhealthy sperm,” Dr Gadêlha
said.
Dr Alberto Darszon, also from the
Mexican university, believes that the
discovery could revolutionise scien-
tists’ understanding of sperm motility.
“So little is known about the intricate
environment inside the female repro-
ductive tract and how sperm swimming
impinge on fertilisation. These new
tools open our eyes to the amazing
capabilities sperm have,” he said.
Dr Corkidi said: “We believe our
state-of the-art 3D microscope will un-
veil many more hidden secrets in
nature. One day this technology will
become available to clinical centres.”How they move
SpermCorkscrew
rotationCentral
axisTail wiggles
on one side
asymmetricallySperm also
rotates in
corkscrew
motion,
allowing it to
swim straight1 2
patrick kiddTMS
[email protected] | @timesdiaryA rum deal
for sailors
The Royal Navy has been sober
for exactly 50 years. Since the
final pouring of the daily rum
ration on July 31, 1970, alcohol has
never passed a sailor’s lips on duty.
Well, hardly ever. It is surprising it
lasted so long. The Admiralty’s
wonderfully named Grog
Committee proposed banning the
daily tot, equal to two doubles,
way back in 1850. In a Commons
debate on the abolition 120 years
later, one James Wellbeloved, a
Labour MP, argued that, far from
impeding performance, a glass of
rum helped to stabilise a sailor’s
stomach in stormy waters. Despite
Wellbeloved offering “sippers or
gulpers” to any MP who backed
him, his attempt to block the ban
was scuttled by the government.The BBC has tried to make
Broadcasting House Covid-secure
but some of the measures confuse
the staff. Jane Garvey, the Woman’s
Hour presenter, says the office has
put in a one-way system with blue
stickers on staircases saying “down
only” next to arrows that point up.
“Just to test you,” she says. Perhaps
the crisis is passing. “Listeners have
gone back to complaining,” Garvey
adds. “I think that’s a positive sign.”a hard rain
Paul Mayhew-Archer, co-writer of
The Vicar of Dibley, has a habit of
leaving his umbrella behind at the
cinema. Eventually he tied his
shoelace to the handle so he
would remember it but when the
film ended he got up and trod on
the lace with his other foot,
making the knot intractable.
Unwilling to drag the
umbrella along the floor, he
tells the My Time Capsule
podcast that he decided to
take the shoe off. This was
fine until he left the cinema in
pouring rain, which forced
Mayhew-Archer to hobblehome with one sodden foot and a
shoe dangling in front of his face.
Still, in every humiliation there’s a
scene for a future sitcom.The biographer Roger Lewis, who
describes himself as “a bit of a
blobby”, has taken the PM’s advice
about losing weight and signed up
with Slimming World, where he
enjoys listening to the excuses of his
fellow porkers for why they can’t
shift the pounds. His favourite, he
writes in The Oldie, was the
woman who explained: “I weigh
more tonight because it’s gone cold
and I’ve got my big knickers on.”bubble trouble
They are taking health warnings
seriously at the Chelsea Arts Club,
where a sign has appeared on the
cubicle door of the gents’ lavatory
instructing: “No heavy petting
outside your bubble.” The Arts
Club has long had a reputation. It
used to hold balls at the Royal
Albert Hall until they were
banned for “nudity, fighting and
unreserved homosexuality”.
Presumably if you wanted to do
the last you had to book.Not all health warnings are about
viruses. The Dalesman magazine
shared a photo of a sign spotted on
a fence near Austwick, North
Yorkshire. “Do not cross the field
unless you can do it in nine seconds,”
it says. “The bulls can do it in ten.”our woman in berlin
Boris Johnson may have a women
problem in his cabinet but they
dominate the Diplomatic Service.
The appointment of Jill Gallard
as our ambassador to Germany
means the top diplomats in the
US, China, Russia, Canada,
Australia, Germany, Italy and
Nato will all be women. We
have come some way from
when our ambassador in
Helsinki turned down a
woman for a posting on the
grounds that “policy is so
often made in the sauna”.