Science - USA (2022-04-08)

SCIENCE science.org 8 APRIL 2022 • VOL 376 ISSUE 6589 149

IMAGE: FRANÇOIS ORANGE/CCMA, UNIVERSITÉ CÔTE D’AZUR

the structure at a particle level.

Michelson et al. present the non-

destructive three-dimensional

imaging of a superstructure

made of thousands of particles

at 7-nanometer resolution, from

which they were able to map

both position and composition.

The authors were also able to

view defects in the crystalline

lattice of the superstructures.

—MSL

Science, abk0463, this issue p. 203

OPTICS

Electrical control of

topological light

Most closed physical systems

are described as Hermitian in

that they can have a single or a

set of distinct resonant modes.

Open systems, however, are non-

Hermitian, and engineering the

gain and loss of such systems can

produce exceptional points where

the resonant modes coalesce.

Ergoktas et al. demonstrate an

electrically tunable system that

allows for reconstruction of the

complex energy landscape and

provides topological control of

light by tuning the loss-imbalance

and frequency detuning of the

interacting modes. Electrical

tuneability provides a route

for exploiting the sensitivity of

exceptional point singularities for

device applications. —ISO

Science, abn6528, this issue p. 184

GRAPHENE

Zooming into trilayer

graphene

Stacking and twisting graphene

layers with respect to each other

can lead to exotic transport

effects. Recently, superconduc-

tivity was observed in graphene

trilayers in which the top and

bottom layers were twisted with

respect to the middle layer by

the same, “magic” angle. Turkel

et al. used scanning tunneling

microscopy to take a closer

look into the stacking struc-

ture. They found that a small

misalignment between the top

and bottom layers caused the

lattice to rearrange itself into a

pattern of triangular domains.

Edited by Caroline Ash

and Jesse Smith

IN OTHER JOURNALS

LUNG DISEASE

Neural signals

control lung fluid

Fluid buildup in the lungs after

injury or infection interferes with

the transfer of oxygen into the

bloodstream. This occurs in acute

respiratory distress syndrome

(ARDS) patients and causes

breathing difficulties. Prior work

has shown that neuroendocrine

substances originating from lung

cells increase during ARDS. By

developing a mouse model for

neuroendocrine cell hyperplasia

of infancy (NEHI), Xu et al. found

that elevated neuropeptides

The domains had a magic-angle

twisted trilayer structure and

were separated by a network of

line and point defects. —JS

Science, abk1895, this issue p. 193

DEVELOPMENTAL BIOLOGY

Generating functional

rat gametes

In the past decade, methods have

been developed to generate germ

cells from pluripotent stem cells

for studies of development and

in vitro gametogenesis. However,

offspring from in vitro–derived

germ cells has only been achieved

in mice. Oikawa et al. extend this

work beyond mice to a second

rodent species, the rat, a leading

animal model for biomedical

research with many physiological

similarities to humans. A stepwise

protocol allows for the production

of fetal stage rat germ cells that

can produce viable offspring upon

maturation in the testis and injec-

tion of the sperm into unfertilized

oocytes. This system will allow

comparative studies and enable

broader execution and analysis of

in vitro gametogenesis. —BAP

Science, abl4412, this issue p. 176

TUMOR IMMUNOLOGY

Monitoring immune

cells in tumors

To predict the effects of immuno-

therapy in cancer, better spatial

understanding of the tumor

microenvironment is needed.

Hoch et al. used multiplex imag-

ing mass cytometry of protein

(immune cell markers) and RNA

(chemokine ligands) targets to

define immune cell interactions

in the tumor microenvironment

of melanoma samples. The

authors found that the chemo-

kines CXCL9 and CXCL10 were

coexpressed in patches with

CXCL13-expressing exhausted

T cells, suggesting that they

recruited B cells and aided in the

formation of tertiary lymphoid

structures in melanoma tumors.

These structures had a spatial

enrichment of naïve and naive-

like T cells, which are involved in

antitumor responses. —DAE

Sci. Immunol. 7 , eabk1692 (2022).

Oomycete spores spread

infection by swarming

using two polar flagella

that coordinate speed and

direction of movement.

PLANT PATHOLOGY

Two flagella cooperate to steer

S

everal of the oomycete Phytophthora species are plant

pathogens that cause diseases such as potato late

blight, sudden oak death, and cocoa black pod dis-

ease. Affecting food crops as diverse as tomato, onion,

soybean, and cucumber, Phytophthora pathogens are

a worldwide threat to food security. Spores of Phytophthora

swarm through thin layers of moisture across soil and leaves,

some initiating infection as they go, steering in response to

environmental signals in their search for a new victim. Tran et

al. investigated how the two flagella on each spore coordinate

for speed and steering. The flagellum at the front is the source

of most of the straightforward action. Not unlike how two

canoeists alter strokes when turning, the spore puts the rear

flagellum on pause while the anterior flagellum changes its

action from sinusoidal waves to full-power stroke. —PJH

eLife 11 , e71227 (2022).