Page 20 - downmagaz.com

IN BRIEF For new stories every day, visit newscientist.com/news

Genes change Fossil life from nearly 4 billion years ago may just be rocks

during pregnancy THE oldest fossils in the world team found a patch of material cross-section, a structure often

might not be anything of the kind, that appears to have survived this seen in deformed rocks, she says.
WOMEN’S bodies go through radical but simply deformed rocks. process relatively unharmed. The chemical analysis also doesn’t
changes during pregnancy, and In 2016, Allen Nutman at the Now Abigail Allwood at the stand up, says Allwood’s team.
now it is becoming clear that there University of Wollongong in Jet Propulsion Laboratory in Nutman rejects the conclusions.
is also upheaval at the gene level. Australia and his colleagues said California and her colleagues have He says that if the objects were
Alicia Smith at Emory University they had found the oldest fossils reanalysed the rocks in Greenland. produced by deformation, they
in Atlanta, Georgia, and her yet, describing stromatolites – They say they aren’t stromatolites wouldn’t all have flat bottoms –
colleagues took blood samples preserved mats of microbes (Nature, doi.org/gfdb45). but they do, and this suggests
from 63 women early and late in sandwiched between layers of Allwood thought it was odd they are stromatolites. Nutman
pregnancy to investigate changes sediment – in 3.7-billion-year-old that the rock face had broken open also criticises Allwood’s team for
in gene expression. Of the 16,000 samples from Greenland. straight through the middle of all focusing on one patch of rock,
genes they looked at, 439 altered Most rocks that old have at the cone-shaped stromatolites. which he says is poorly preserved.
their activity between the first and some point been carried deep into So she cut 10 centimetres into the However, Allwood points out
third trimester of pregnancy. the planet, where pressure and rock and found that they are long that the same rocks were the
Many of the changes occurred in heat destroy fossils. But Nutman’s ridges, with a roughly triangular centrepiece of the original paper.
genes involved in the immune and
circulatory systems. For instance,
Nicotine gives mice
there was increased expression of
alpha-defensin genes, which help to
fight disease-causing bacteria, fungi hyperactive pups
and viruses. This probably protects ESO/L. CALÇADA & OLGA CUCCIATI ET AL.
the fetus from microbes like listeria EXPOSURE to nicotine has
that can cause miscarriage and negative effects that echo down
pre-term birth, says Smith. the generations – in mice, at least.
There were also changes in genes Male mice exposed to nicotine
that protect the fetus from the had offspring with signs of a
mother’s immune system. And genes mouse version of attention deficit
involved in oxygen transport in blood hyperactivity disorder (ADHD).
became more active. This is probably To check the impact of paternal
because women produce more nicotine use, Pradeep Bhide at
blood when pregnant to deliver Florida State University and his
adequate oxygen to the fetus and colleagues put nicotine in water
safeguard against blood loss during given to 12 male mice and, after
delivery (PLoS One, doi.org/cvwg). 12 weeks, mated them with females
Smith says knowing how gene never exposed to the chemical.
activity changes in the course of The offspring were between
healthy pregnancies might allow 30 and 50 per cent more active
us to develop tests that can pick than normal mice. They were also Early giant of the universe discovered
up abnormal changes. worse at trying to escape from a
maze. Moreover, the males, but A SURVEY of the early universe had many more billions of years to
PLAINPICTURE/JANKLEIN exploring new objects — an formed just 2 billion years after the been seen before, but astronomers
not the females, spent less time
has revealed a huge structure that
grow as gravity pulled them together.
Pieces of the supercluster had
indicator of attention deficiency.
big bang. Its existence could teach
The brains of the male offspring
hadn’t realised that they were
us more about how the universe
had levels of dopamine 30 per
cent lower than expected and half developed and hints at how much looking at parts of a larger whole.
Using the VIMOS instrument
dark matter was around then.
the dopamine receptors usually The half-formed supercluster of on the European Southern
present in a mouse brain. Both galaxies, nicknamed Hyperion after Observatory’s Very Large
characteristics are associated with a Titan from Greek mythology, is the Telescope, which gives a more
ADHD. No significant changes largest object seen from that epoch. panoramic view of very distant
were found in the brains of female Hyperion’s mass at just 2 billion regions of space, a team led by
mice (PLoS Biology, doi.org/cvwq). years old is 1 million billion times that Olga Cucciati at the National Institute
Bhide suspects that nicotine of the sun. This puts it in the same for Astrophysics in Bologna, Italy,
may change gene expression in league as the largest structures in were able to join the dots (Astronomy
sperm. Why male offspring are the universe today, but those have & Astrophysics, doi.org/cvwj).
worse affected isn’t known.

18 | NewScientist | 27 October 2018