SCIENCE science.org 22 APRIL 2022 • VOL 376 ISSUE 6591 366-B
GENETICS
Can repetitive
DNA cause disease?
Repetitive DNA sequences litter
the human genome. Although
they are mostly silent, some can
“jump” around, duplicating and
inserting themselves through-
out genomic DNA, which can
potentially disrupt nearby genes,
modulate transcription, or elicit
immune responses. This inser-
tional mutagenesis is especially
prominent in cancer and has
also been described in devel-
opmental, degenerative, and
autoimmune diseases. However,
it is unclear whether this process
contributes to pathogenesis
or if it arises as a consequence
of other genetic and epigen-
etic changes. In a Perspective,
Burns considers the evidence
and discusses mechanisms
for insertional mutagenesis
in pathogenesis and whether
repetitive DNA is a widespread
cause of disease. —GKA
Science, abl7399, this issue p. 353
TRAFFIC SAFETY
When behavioral
nudges fail
Do traffic safety interventions
work? Hall and Madsen present
evidence from a study in Texas
showing that the number of
crashes actually increases by
a few percentage points when
motorists are confronted with
displays indicating the number
of road fatalities in the area (see
the Perspective by Ullman and
Chrysler). The authors sug-
gest that this counterintuitive
finding results from a cogni-
tive overload experienced by
drivers when confronted with
multiple notices and instruc-
tions on complex stretches of
road, leading to distraction.
They conclude that traffic safety
“nudges” need to be carefully
designed and positioned to
avoid backfiring. —AMS
Science, abm3427, this issue p. 370;
see also abq1757, p. 347
CELL BIOLOGY
Membrane repair
in target cell defenses
Killer T cells destroy virus-
infected and cancer cells by
secreting two protein toxins
that act as a powerful one-two
punch. Pore-forming toxins,
perforins, form holes in the
plasma membrane of the target
cell. Cytotoxic proteins released
by T cells then pass through
these portals, inducing target
cell death. Ritter et al. com-
bined high-resolution imaging
data with functional analysis
to demonstrate that tumor-
derived cells fight back (see the
Perspective by Andrews). Protein
complexes of the ESCRT family
were able to repair perforin holes
in target cells, thereby delaying
or preventing T cell–induced
killing. ESCRT-mediated mem-
brane repair may thus provide
a mechanism of resistance to
immune attack. —SMH
Science, abl3855, this issue p. 377;
see also abp8641, p. 346CATA LYS I S
Sourcing hydrogen with
ceramic reactors
An alternative to directly trans-
porting hydrogen produced
at large scales through steam
reforming for applications such
as vehicular fueling is smaller-
scale, on-site production from
methane or carriers such as
ammonia. The hydrogen pro-
duced must be separated from
co-produced carbon dioxide or
nitrogen. Proton ceramic electro-
chemical reactors can extract
pure hydrogen from gas mix-
tures by electrolytically pumping
protons across the membrane
at 800°C, but as the extraction
proceeds, temperature gradi-
ents and entropic effects lead
to efficiency drops. Clark et al.
developed a nickel-based glass-
ceramic composite interconnect
that allowed for the design of a
more complex reactor pathway
(see the Perspective by Shihand Haile). Counterflowing
streams balanced heat flows
and maintained stable operating
conditions that enabled 99%
efficiency of hydrogen recovery.
—PDS
Science, abj3951, this issue p. 390;
see also abo5369, p. 348SUPERCONDUCTIVITY
Double horn points
to an exotic state
The so-called Fulde-Ferrell-
Larkin-Ovchinnikov (FFLO)
state, a particular kind of super-
conducting order in which the
order parameter oscillates in
space, has fascinated physicists
because it is tricky to stabi-
lize. Kinjo et al. used nuclear
magnetic resonance (NMR)
measurements to observe a
signature of the FFLO state in
the material strontium ruthe-
nate (see the Perspective by
Pavarini). The modulation in the
superconducting order param-
eter caused a corresponding
modulation of spin density,
which resulted in a peculiar,
double horn–shaped structure
of NMR intensity for a certain
range of temperatures and
applied magnetic field. —JS
Science, abb0332, this issue p. 397;
see also abn3794, p. 350METAMATERIALS
Actively structuring light
The development of meta-
surfaces has provided a route
to replacing bulk optical
components with thin layers
of engineered materials. In a
Review, Dorrah and Capasso
highlight some of the recent
advances in wavefront shaping
using multifunctional meta-
optics. They focus on the ability
to tune the response of the
metasurface by simply tuning
one or more degrees of freedom
of incident light, for example,
by varying its angle of inci-
dence, polarization, wavelength,
or phase. The key feature of
these metasurfaces is thatalthough they are static, they
can produce a tunable response
without the need for complex
switching. These develop-
ments enable multifunctional
and lightweight components
for technologies such as
augmented and virtual reality
displays, drone-based sensing,
and endoscopy. —ISO
Science, abi6860, this issue p. 367CANCER GENOMICS
A signature
accomplishment
Tumor development is associ-
ated with the accumulation
of mutations in the genome.
Depending on the causes of a
given cancer, such as environ-
mental exposures or DNA repair
abnormalities, these mutations
can form a specific pattern
called a mutational signature.
Many mutational signatures
have already been reported
in cancer, but by performing
whole-genome sequencing on
a particularly large collection of
cancer samples, Degasperi et
al. not only confirmed previ-
ously reported signatures, but
also discovered many rarer
ones (see the Perspective by
Szüts). The authors character-
ized these signatures, tried to
elucidate the underlying biology
where possible, and then pro-
vided an algorithm for applying
these findings to individual
patients to help personalize
cancer treatments. —YN
Science, abl9283, this issue p. 368;
see also abo7425, p. 351CORONAVIRUS
Acting against Omicron
The rapid spread of the Omicron
variant of the severe acute
respiratory syndrome coro-
navirus 2 (SARS-CoV-2) virus
was partly due to its ability to
evade antibodies elicited against
the viral spike protein of early
variants. Zhou et al. identified
antibodies that maintained their
ability to neutralize the OmicronRESEARCHEdited by Michael FunkALSO IN SCIENCE JOURNALS