Science - USA (2021-12-17)

SCIENCE science.org 17 DECEMBER 2021 • VOL 374 ISSUE 6574 1459

the pituitary-gonadal feed-
back loop, which suppresses
pituitary FSH secretion and
allows for the development of
only a single follicle in humans.
More than 20 years ago, it was
demonstrated that inhibin A
displays specific activity by
binding to an activin recep-
tor and an inhibin A–specific
co-receptor betaglycan. Brule
et al. identified the inhibin B
co-receptor, which has evaded
discovery for so long, as
the transmembrane protein
TGFBR3L (see the Focus
by Woodruff). The authors
demonstrate the critical role
that this co-receptor plays
in female fertility, suggesting
that targeting this pathway
may provide new methods to
improve the regulation of fertil-
ity. — TPB
S c i. Ad v. 10.1126/sciadv.abl4391,
10.1126/sciadv.abn1373 (2021).

QUANTUM SIMULATION

Quantum scrambling
Information spreading in
interacting quantum systems
is of relevance to a wide range
of settings, from black holes to
strange metals. Mi et al. used
the Sycamore quantum pro-
cessor to study this process.
Through judicial design of
quantum circuits, the research-
ers were able to separate
the contributions of opera-
tor spreading and operator
entanglement. Measuring the
mean value and fluctuations

MICROBIOLOGY

Prince among tiny

vampires

Life clings on in even the most

unpromising of Earth’s habitats.

A series of hypersaline alkaline

lakes on the northeastern

Mongolian plateau is home to

several unique communities,

including extremophile bacte-

ria. Yakimov et al. discovered

that the anaerobic, purple

sulfur photosynthetic bacterium

of a specific correlator enabled

quantifying these distinct con-

tributions. —JS

Science, abg5029, this issue p. 1479

QUANTUM SIMULATION

Establishing order,

time after time

The formation of discrete time

crystals, a novel phase of matter,

has been proposed for some

many-body quantum systems

under periodic driving condi-

tions. Randall et al. used an array

of nuclear spins surrounding

a nitrogen vacancy center in

diamond as their many-body

quantum system. Subjecting the

system to a series of periodic

driving pulses, they observed

ordering of the spins occurring

at twice the driving frequency, a

signature that they claim estab-

lishes the formation of a discrete

time crystal. Such dynamic con-

trol is expected to be useful for

manipulating quantum systems

and implementing quantum

information protocols. —ISO

Science, abk0603, this issue p. 1474

MUCOSAL IMMUNOLOGY

A fluent defense

Secretory immunoglobulin

A (IgA) is known to be a key

effector molecule in establish-

ing effective antiviral immunity

in the lungs, but the specific cell

types producing this mucosal IgA

and their physical locations are

unclear. Oh et al. analyzed pulmo-

nary IgA-secreting cells in mice

after prior influenza infection or

after intranasal immunization

with an adjuvanted recombinant

neuraminidase influenza vac-

cine. Both treatments enhanced

antiviral immunity and IgA

production when administered

intranasally rather parenterally.

The IgA responses were medi-

ated through a combination of

lung-resident memory B cells,

plasmablasts, and plasma cells.

These findings add to growing

evidence that mucosal vaccina-

tion strategies show enhanced

efficacy in establishing frontline

mucosal immunity against respi-

ratory pathogens. —IRW

Sci. Immunol. 6 , eabj5129 (2021).

An experimental investigation
of quantum scrambling on
a superconducting chip yields
observations of the so-called
butterfl y velocity.

Resealing of a wounded nuclear envelope, shown in this 3D reconstruction,

is essential for maintaining genome integrity.

CELL BIOLOGY

Force regulation during repair

T

he cell nucleus is surrounded by a double membrane

structure known as the nuclear envelope (NE). Ruptures

in the NE compromise nuclear-cytoplasmic compart-

mentalization and contribute to genome instability and

pro-inflammatory responses. Resealing of the wounded

NE is mediated by the Endosomal Sorting Complex Required

for Transport (ESCRT) machinery, a highly conserved

membrane-remodeling pathway. During repair, the mechani-

cal strain imposed by the cytoskeleton needs to be relieved

to counteract intranuclear pressure. Wallis et al.found that

the ESCRT-associated protein BROX regulates the mechani-

cal properties of the NE during repair. BROX bound to the

nucleoskeleton-cytoskeleton linker protein Nesprin-2G and

promoted its removal from compression sites, which facili-

tated efficient membrane resealing and protected genetic

material from damage. —SMH Dev. Cell 56 , P3192 (2021).

Edited byCaroline Ash

andJesse Smith

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