366 22 APRIL 2022 • VOL 376 ISSUE 6591 science.org SCIENCE
Caspian tern (Hydroprogne caspia) juveniles rely on parental guidance, chiefl y from their fathers, to ensure safe migration.MIGRATIONFather knows best
M
any birds migrate long distances between breeding and
wintering grounds. Although we know that in many cases
naïve birds follow more experienced birds, we still know
little about the details of which one is doing the leading.
Byholm et al. monitored migration in Caspian terns using
GPS trackers and found that family groups generally migrated
together, with a single parent leading the way. Both male andfemale parents led the group, but fathers were more likely to be
guides. Individuals that lost their guides tended to fall victim to
birds of prey. The authors did report that some fathers would
act as guides for unrelated juveniles. When migrating solo for
the first time, subadult terns followed the same route they took
with their parents, indicating cultural inheritance of migration
knowledge. —SNV Nat. Commun. 13 , 1566 (2022).been called ladderanes because
when they are drawn flat, the
shared edges look like the rungs
of a ladder. However, in three-
dimensions, the geometry is
more reminiscent of a stairway.
Ray et al. report a synthesis of
ladderanol, an alcohol-capped
component of these lipids that
selects between the two product
mirror images (natural and
unnatural) at a late stage. They
achieved the requisite selectiv-
ity using a hydrogen-bonding
squaramide catalyst to guide a
nitroalkyl Michael addition. —JSY
Angew. Chem. Int. Ed. 10.1002/
anie.202201584 (2022).IMMUNOMETABOLISM
Steely response to cancer
Ferroptosis is a form of
programmed cell death that
requires iron and the accumula-
tion of lipid peroxides. Cancer
cells undergo ferroptosis indynamics simulations to test
this scenario. They found that
migration of the giant planets
in the early Solar System could
scatter numerous planetesimals
into the main belt. Most were
then ejected by interactions
with Jupiter, with only a small
fraction evolving onto stable
orbits. To explain one Ceres-
sized object surviving in the
main belt, there must have origi-
nally been several thousand in
the outer Solar System. This is
consistent with estimates based
on the formation of Uranus and
Neptune. —KTS
Icarus 379 , 114933 (2022).
ORGANIC CHEMISTRY
Ladders in the mirror
Ammonia-oxidizing bacteria
produce a fascinating class of
lipids that have multiple edge-
sharing four-carbon rings in
their tails. These molecules have
response to immunotherapy,
but how this process is
regulated is not clear. Liao et al.
explored whether factors within
the tumor microenvironment
were involved in tumor ferropto-
sis. They studied specific lipids
and lipid metabolic enzymes
that influence antitumor immu-
nity and found that arachidonic
acid synergized with T lympho-
cyte–derived interferon-g to
produce pro-ferroptotic effects.
A combination of PD-L1 immu-
notherapy and arachidonic acid
supplementation was tested as
a preclinical treatment strategy
to sensitize tumors toward
ferroptosis and reduce tumor
growth in mice. —PNK
Cancer Cell 40 , 365 (2022).NEURODEVELOPMENT
Tuning layers of the brain
The cortex of the adult mam-
malian brain is made up of sixlayers of neurons, but not all
regions of the brain show layers
of similar depth and complex-
ity. Layer 4, which receives
sensory information from the
thalamus, is thicker in the
sensory cortex than it is in the
motor cortex of the brain. Sato
et al. examined communication
between thalamocortical axons
and the developing cortex in
mice. Postnatal ablation of
thalamocortical axons showed
how dependent the normal
development of layer 4 is on
these neuronal connections.
Without thalamocortical axon
connections, layer 4 in the
somatosensory cortex had
fewer neurons than it normally
would. Even minute alterations
in the laminar architecture of
the brain’s cortex can have
consequences for cognitive,
mental, or psychiatric disor-
d e r s. — PJ H
eLife 11 , e67549 (2022). PHOTO: MICHAEL WOODRUFF/SHUTTERSTOCK