12 October 2019 | New Scientist | 7GREY whales are one of the
longest-lived mammals in
existence. The secret to their
long lives? A resilience to stress,
according to the first genetic
sequencing of the animals.
The genes for stress resistance
are also shared by other long-lived
animals, like naked mole rats,
which can outlive mice by 25 years,
give or take, and humans. It is this
stress resistance that protects most
long-lived animals from cancer,
says Dmitri Toren, now at the
Romanian Academy in Bucharest.
Toren and his colleagues are
investigating ageing and why
some animals are able to live long
lives. The team decided to study
the grey whale because it can live
into its 70s, and is considered to be
the eighth longest-lived mammal.
In order to study cells taken
from grey whales, a member of the
team had to travel to Chukotka, an
autonomous area of Russia, where
annual whale hunts are regulated
by the International Whaling
Commission. “It was challenging
to get a biopsy,” says Toren. “He had
to fly there and wait for half a year.”
Once the team had liver and
kidney tissue from two grey
whales, the researchers looked at
the genes that were switched on
in each sample. They sorted these
“expressed” genes into categories
based on their functions, and
focused on those that had
previously been linked to ageing.
These included those that code for
proteins that affect how well thebody can get rid of faulty proteins
and maintain and repair DNA,
as well as others involved in the
workings of the immune system.
Toren and his colleagues then
compared the levels of gene
expression to that of two other
long-lived whales – the bowhead
and minke – as well as the
relatively short-lived mouse, the
cow and the relatively long-lived
human and naked mole rat. All of
the animals were young adults.
It is difficult to compareindividual genes across species,
so instead, the team ranked the
expression of genes based on
their functions for each species.
When they compared these
rankings between species, they
found that long-lived animals had
higher levels of gene expression
associated with the maintenance
of DNA and immune cells, and the
flushing out of damaged proteins.
This may explain why whales are
thought to be protected from
cancer (bioRxiv, doi.org/dcfr).
“That stress resilience is
important is a very plausible
hypothesis,” says Lorna Harries
at the University of Exeter, UK.
“We know that your molecular
stress response tends to decline
with age... if you can maintain
your stress responses, the chances
are you’re going to age better.”
Harries points out that the
researchers may have missed
some differences between the
animal species, and that, given
the team were only able to study
two grey whales, more research is
needed to confirm the findings. ❚
For more animals that combat
ageing see page “ SpiNNaker can simulate
the behaviour of
77,0000 neurons in
the sensory cortex”Longevity
Jessica Hamzelou
CL
AUDIOCONT
RE
RAS/NATURE^PICTURE
LIBRA
RYComputing
Supercomputer
simulates key brain
centre in real time
A BRAIN-inspired computer can now
simulate part of the sensory cortex
in real time, using tens of thousands
of virtual neurons. It is the first time
such a complex simulation has run
this fast and could be used to help
build better brains for robots.
The SpiNNaker supercomputer
at the University of Manchester, UK,
features 57,000 specialised chips
with a total of 1 million processing
units, known as cores. It is designed
to run programs that simulate
how biological neurons behave.
The computer shuttles
information around in a similar way
to the brain, says Oliver Rhodes,
who led the research. Standard
supercomputers send big blocks
of data at set times, but SpiNNaker’s
cores can transmit small blocks
to hundreds of other cores
simultaneously whenever required.
Now Rhodes’s team has shown
that SpiNNaker can simulate the
behaviour of 77,0000 neurons
in the sensory cortex, equivalent
to about 1 square millimetre’s
worth, as fast as it happens in thebrain and for up to 12 hours
(arxiv.org/abs/1909.08665).
“We can run this at the same
speed as biology, which is quite
a big achievement,” he says.
This is a stepping stone to more
complex models of things like
sensory processing, says Rhodes.
The research is a big step towards
large-scale simulations of brain
processes, says Brad Aimone at
Sandia National Laboratories inNew Mexico. Researchers will have
to run hundreds of simulations to
confirm results, so making them
fast is crucial. “Now the burden
is back on to the neuroscientists
to actually build models that can
scale to this level,” he says.
Markus Diesmann at the
Jülich Research Centre in Germany,
who designed the model used by
SpiNNaker, says real-time operation
means the chips could also be useful
in robotics. “You can really transfer
principles and algorithms that
you’ve uncovered in nature into this
artificial brain living in a robot.” ❚
Edd GentThe key to a long life may be
genes that protect against stress
Grey whales can live
long lives, surviving
well into their 70s