CREDITS (FROM T0P) HAGEET AL.; HOUET AL.1086 6 MARCH 2020 • VOL 367 ISSUE 6482 sciencemag.org SCIENCE
screen using CRISPR-Cas9
with single-cell transcriptomics
suggested critical roles for
hundreds of micropeptides.
Micropeptides encoded by
multiple short, upstream ORFs
form stable protein complexes
with the downstream canonical
proteins encoded on the same
messenger RNAs. —SYM
Science, this issue p. 1140;
see also p. 1074TRANSCRIPTION
RNA life span at
single-cell resolution
RNA transcripts are an eas-
ily accessed representation of
gene expression, but we lack a
comprehensive view of the life
span of RNA within the single
cell. Battich et al. developed
a method to sequence mes-
senger RNA labeled withQUANTUM SIMULATION
Gauge invariance
with cold atoms
There is considerable inter-
est in developing quantum
computational technologies
that can simulate a series of
physical phenomena inacces-
sible by classical computers.
Mil et al. propose a modular
scheme for quantum simulation
of a U(1) lattice gauge theory
based on heteronuclear spin-
changing collisions in a mixture
of two bosonic quantum gases
isolated in single wells of a one-
dimensional optical lattice. They
engineered the elementary
building block for a single well
and demonstrate its reliable
operation that preserves the
gauge invariance. The potential
for scalability of the proposed
scheme opens up opportuni-
ties to address challenges
RESEARCH
in quantum simulating the
continuum limit of the gauge
theories. —YS
Science, this issue p. 1128HIV
Clearing a path for
an HIV cure
Curing HIV is more feasible if we
better understand the forma-
tion of the latent viral reservoir.
Leyre et al. studied longitudi-
nal blood and tissue samples
obtained from individuals during
acute HIV infection. The large
pool of infected cells present
at the early stages of infection
did not survive antiretroviral
treatment. Infected cells at later
stages were more prevalent in
lymphoid tissues than in blood.
These results show that most
infected targets are cleared
with early treatment, butHIV-positive cells that remain
after a certain stage are more
likely to persist. These persis-
tent cells are the ones that will
need to be eradicated for a cure
to be achieved. —LP
Sci. Transl. Med. 12 , eaav3491 (2020).MOLECULAR BIOLOGY
Expanding the human
proteome
Using mass spectrometry,
ribosome profiling, and several
CRISPR-based screens, Chen
et al. identified hundreds of
previously uncharacterized
functional micropeptides in
the human genome (see the
Perspective by Wei and Guo).
Pro tein translation outside of
annotated open reading frames
(ORFs) in messenger RNAs and
within ORFs in long noncoding
RNAs is pervasive. A functionalIN SCIENCE JOURNALS
Edited by Michael FunkSOLAR CELLSGrowing perovskite on textured silicon
W
ide–band gap perovskites could boost the efficiency of
silicon solar cells by forming tandem cells, but usually the
perovskite must be grown on a smoothed side of the silicon
cell because the material grown on the rough light-trapping
side often does not fully coat the silicon surface and its
rough texture is prone to phase separation. Hou et al. grew thick
films of a perovskite with a band gap of ~1.68 electron volts andused a passivant, 1-butanethiol, to limit its phase separation. The
tandem cells had a certified power conversion efficiency of
25.7% and had negligible losses after 400 hours of operation.
—PDS Science, this issue p. 1135Cross-sectional scanning electron microscope image of textured crystalline
silicon, which can form the bottom cell in perovskite-silicon tandem solar cellsVibrational spectroscopy in
an electron microscope
Hage et al.,p. 1124Published by AAAS