ADVANCES
14 Scientific American, April 2022wangshin Kim/Science Sourcecameras at nearly 4,000 frames
per second during a battery of
tests. They used these record-
ings to construct 3-D models of
the diminutive beetle and calcu-
late its aerodynamics.
The team found that instead
of flapping their wings up and
down, featherwing beetles
loop them in a “remarkable”
figure-eight pattern, says study
co-author Dmitry Kolomenskiy,
a physicist studying fluid me -
chanics at Moscow’s Skolkovo
Institute of Science and Tech-
nology. After the bristled wings
unfurl from their protective
cases, known as elytra, they
mirror each other as they move,
clapping to^ gether both in front
of and behind the insect—
Kolomen skiy says the motion
is reminiscent of an extreme
version of swim strokes such
as the butterfly. The elytra
stabilize the beetle and its
churning wings, preventing it
from spinning.
The pattern’s resemblance
to swimming particularly
intrigues Arvind Santhanakrish-
nan, a mechanical engineer who
studies tiny insects’ aerodynam-
ics at Oklahoma State Univer-
sity. “Typically this type of pad-
dling is seen in small aquatic
crustaceans such as water
fleas,” says Santhanakrishnan,
who was not involved with the
study. “It was quite surprising
to see that a similar strategy
was used by the tiny feather-
wing beetles to generate lift.”
Kolomenskiy and his col-
leagues hope to illustrate the
flight patterns of other, simi-
larly minuscule insects. They
say their findings may influence
how engineers shrink flying
technology—although Kolo-
menskiy admits it would take
a major engineering feat for a
drone to approach the propor-
tions of a featherwing beetle.
“Probably not as small,” he says.
“But that’s to be explored.”
— Jack Tamisiea
MICROBIOLOGYGenes under Wraps
An ancient molecule helps bacteria take control of their genome
DNA has a knotty problem. Thousands of
times longer than the cell that contains it, this
intricate strand of As, Ts, Gs and Cs must fold
itself into a compact package. But the thin dou-
ble helix molecule can’t jam itself in any which
way, lest it wind up horribly knotted. What’s
more, the cell needs certain segments of the
strand—particular genes— to remain accessi-
ble to protein-making machinery while keep-
ing others tucked away and turned off. It’s like
playing Tetris with a tangled ball of yarn.
Nucleus-containing “eukaryotic” cells, the
type found in humans, plants and animals, rely
on complex interactions between chemical tags
and specialized proteins to provide instructions
about what genes to turn on and when—a sys-
tem called epigenetics. For decades scientists
thought epigenetic regulation was unique to
eukaryotic cells and lacking in simpler ones,
such as bacteria. But a series of newer findings
has challenged that idea.
“Bacteria are way more sophisticated than
anyone realized,” says David Low, a micro-biologist at the University of California,
Santa Barbara.
New studies by University of Michigan bio-
chemists Ursula Jakob and Peter Freddolino
reveal that interactions between DNA-binding
proteins and an ancient molecule called poly-
phosphate help to switch bacteria’s genes on
and off on a broad scale. Not only do these
findings tell scientists more about such organ-
isms’ basic biology, but they could also help
researchers fine-tune genetically engineered
bacteria for biotechnology—and even contrib-
ute to new antibiotics.
“Bacteria are carrying around the seeds
of their own destruction, and we might be able
to remove the repression that’s keeping [those
seeds] down,” Freddolino says.
Eukaryotic cells have long been known to
use multiple layers of regulation, controlling
which genes are active and how much of a
given protein each one makes. Bacterial DNA,
on the other hand, was typically portrayed in
textbooks as a long piece of inert string, wait-Artificially colored view of E. coli