01/02.2020 | THE SCIENTIST 17approach,” saysIan Adams, a devel-
opmental biologist at the University
of Edinburgh’s MRC Human Genet-
ics Unit who was not involved in the
research. Rather than look for transpo-
son activity in a specific disorder, “it’s
casting a much broader net in trying to
find what type of diseases this class of
mutations could be contributing to.”This approach is important, agrees
Adams’s MRC Human Genetics Unit
colleague Jose Garcia-Perez, a trans-
posable elements expert who was also
not involved in the new research. In the
last few years, two studies have used a
tool developed around the same time as
MELT to search for de novo mobile ele-
ments in people with autism spectrum
disorder, but neither identified any that
were likely to be responsible for the
patients’ symptoms (Am J Hum Genet,
98:667–79, 2016; Science, 360:327–31,
2018). “[Gardner’s] study shows that,
no matter what’s [been found] recently,
it’s something that should be explored in
further detail in the future,” says Garcia-
Perez. “[The study] actually shows a
real connection between... transposi-
tion with that particular [type of ] dis-
order.” Koboldt adds: “The reason this
is an important study is that it estab-
lishes [that these] variants do occur
and [that] they can be pathogenic.”
Gardner says he hopes that his meth-
ods can be used to explore other diseases,
from both a research and a clinical per-
spective. Adams says MELT does appear
to be “widely applicable to other datasets.”
Such a tool could be a boon to research
on transposons, given that their move-
ments are often missed by normal screen-
ing tools, Adams adds. “I think [MELT is]
something that could be readily built into
existing pipelines.” —Jef AkstVery Hungry
Caterpillars
Armed with a paring knife, evolu-
tionary biologist Genevieve Kozak often
ventures into cornfields in the North-
eastern US to cut open plant stalks and
look for larvae of the European corn
borer moth. The caterpillars burrow
inside the plants to overwinter, leaving
a telltale hole that signals to researchers
such as Kozak which plants to open up.
Slicing through the stalks can be a
challenge: back in 2011, “the first time
I went out there, I cut my thumb,” says
Kozak, then a postdoc in Erik Dopman’s
lab at Tufts University, and now a pro-
fessor at the University of Massachu-
setts–Dartmouth. Once she has the
plants cracked open, though, the cat-
erpillars inside aren’t that difficult to
gather. Each winter, after going through
their last molt before becoming pupae,
corn borers (Ostrinia nubilalis) enter a
dormant state of activity known as dia-pause. To survive this vulnerable time,
the larvae hide out someplace where
they won’t be disturbed. For corn bor-
ers, that place is inside the stalks of the
plants, which also serve as their pri-
mary food source when they wake up
in the spring.
Although most commercially grown
corn in the US is genetically engineered
to be resistant to corn borers, the moths
are a major problem for organic farm-
ers, who can’t plant engineered crops
or use chemical pesticides if they are to
meet regulatory standards for organic
products set by the United States
Department of Agriculture. And over
the last few decades, a new challenge
has emerged in the battle against these
pests. As global temperatures rise and
winters become shorter, some popula-
tions of corn borer larvae in the US haveCHANGING WITH THE TIMES: Mutations in
two genes associated with circadian rhythms
may help the corn borer moth adapt to
climate change.There is tremendous value
for these families that get a
diagnosis.
— Dan Koboldt, Steve and Cindy Rasmussen
Institute for Genomic Medicine
Nationwide Children’s HospitalSARA GREGG