Amish population, Montasser
et al. identified a genetic variant
that results in an amino acid
change in the beta-1,4-galacto-
syltransferase 1 protein and
is correlated with lower levels
of cardiovascular disease.
Investigation of the mutant
protein showed that it affects
genes associated with low-
density lipoprotein cholesterol
(LDL-C), and mice engineered
to express the mutant protein
exhibited a 38% decrease in
blood LDL-C levels. This study
suggests that such genomic
sequencing and analysis can
link genotype to phenotype and
identify potentially clinically
actionable pathways to treat
disease. —LMZ
Science, abe0348, this issue p. 1215
PLANT SCIENCE
Dyed roots reveal inner
complexity
Plant roots do so much more
than just hold a plant up. As a
site for air storage during flood-
ing, mycorrhizal symbiosis, or
carbohydrate storage, the more
complex root can tap more
complicated functions. Taking
advantage of a dye that stains
less the deeper it penetrates
the tissue, Ortiz-Ramírez et al.
applied fluorescence-activated
cell sorting to the complex
cell layers of the maize root.
RNA sequencing applied to
the single-cell pools defined
a developmental map and
showed that the mobile tran-
scription factor SHORT-ROOT
travels through multiple cell
Edited by Caroline Ash
and Jesse Smith
IN OTHER JOURNALS
SIGNALING
Explaining fast
receptor signaling
Stimulation of the small gua-
nosine triphosphatase Ras,
which is activated in response
to receptor activation at the
cell surface, can occur sur-
prisingly rapidly. The time
for activation of the guanine
nucleotide exchange factor
Son of Sevenless (SOS), which
activates Ras, has been esti-
mated to take about a minute.
In cells, however, activation
occurs in only a few seconds.
Mathematical modeling and in
vitro experiments by Huang et
al. showed that this reflects the
processive activation of multiple
SOS molecules, with one SOS
molecule activating hundreds
of Ras molecules. Thus, the
layers and directs this grass
root’s anatomical complexity.
— PJ H
Science, abj2327, this issue p. 1247
BIOCHEMISTRY
Revealing the oncogenic
effects of RIT1
Various mutant forms of
the signaling protein RAS
underlie multiple types of
cancers, including lung cancers.
Mutations or chromosomal
amplifications in the RAS-
related protein RIT1 have been
found in about 15% of lung
adenocarcinomas. Lo et al. per-
formed comparative multiomics
in lung epithelial cells expressing
mutant or wild-type forms of
RIT1 or RAS. In contrast to RAS,
which promoted oncogenic and
metastasis-associated changes
when mutated, RIT1 promoted
these changes whether mutated
or not. The findings suggest that
overexpression of wild-type RIT1
may be an unappreciated driver
in tumor development. —LKF
Sci. Signal. 14 , eabc4520 (2021).
MOLECULAR BIOLOGY
Maturation for survival
Although cells with defects
in DNA replication usually
die under stress conditions,
some cells acquire new muta-
tions and survive. Sun et al.
identified an error-prone,
stress-induced Okazaki frag-
ment maturation pathway
that induces tandem duplica-
tions and enables the survival
of cells that have defects in
removing the 5 9 RNA-DNA
flap during DNA replication. In
these cells, stress conditions
activate DUN1 signaling and
induce conversion of the 5 9
flap to a 3 9 flap that can form
secondary structures and
be extended and ligated to
the downstream DNA frag-
ment, generating alternative
duplication mutations similar
to the ones in human cancers.
The revealed information is
analogous to the mechanism in
cancer cell evolution and drug
resistance. —DJ
Science, abj1013, this issue p. 1252
SCIENCE science.org 3 DECEMBER 2021 • VOL 374 ISSUE 6572 1211
A fl uorescence microscopy cross
section reveals structured layers of
cells in the root tissue of the grass
PHOTOS: (LEFT TO RIGHT ORTIZ RAMÍREZ Setaria viridis.
ET AL
.; ALVAREZ/ISTOCKPHOTO.COM
Listening to audiobooks reveals how the brain separates linguistic
aspects of speech from the sounds of speech.
NEUROSCIENCE
Echoes of speech in the brain
T
he brain’s response to people talking is shifted by the
listener paying attention and understanding the speech.
The brain still tracks sounds that the listener is trying to
ignore. The ability to track the neural response to speech
may help in settings where a person is unable to respond
in other ways. Gillis et al. tracked neural responses to the
linguistic aspects of speech while controlling for the acoustic
aspects of the speech. Young adult subjects were asked to pay
attention to audiobook stories read by the same speaker as
electroencephalography (EEG) data were collected. The results
show the brain EEG reflecting linguistic aspects of speech over
and above the sounds of speech. —PJH
J. Neurosci. 10.1523/jneurosci.0812-21.2021 (2021).