Human gene recount
ups the number
Counting how many genes are in the
human genetic instruction manual, or
genome, isn’t easy. A gene’s very definition has changed in the last 15 years.
Genes used to be defined as stretches
of DNA with instructions that are copied into RNA and turned into proteins.
But scientists now know that not all
genes produce proteins; some make
RNAs with other functions in a cell.
Researchers still don’t agree on how
many “protein-coding genes” there
are. Estimates range from 19,901 to a
new count of 21,306, published August
20 in BMC Biology. The number of
RNA-producing genes is even murkier,
says Steven Salzberg, a biostatistician
at Johns Hopkins University. His team
found 25,525 RNA-producing genes,
for a total of 46,831 human genes. “I
will not be surprised if 10 years from
now, we still don’t have an agreed-upon
number,” Salzberg says.
— Tina Hesman Saey
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Suprising beauty found inside kidney stones
Crystal formations in Yellowstone’s hot springs helped researchers understand
stones much closer to home — in our kidneys. In his field research, geobiologist
Bruce Fouke had never seen a stone that “doesn’t grow and dissolve, grow and dissolve.” But that went against the medical dogma that kidney stones don’t dissolve.
So Fouke, of the University of Illinois at Urbana-Champaign, teamed up with an
interdisciplinary research group for “a good, geological look at a kidney stone.”
Most kidney stones are made of primarily calcium and oxalate, found in nuts,
beets and other foods. Shining ultraviolet light on thin sections of a kidney stone
revealed colorful mineral strata (green, light blue and yellow layers in fluorescence
micrograph above) and collections of new growth (dark blue) that Fouke describes
as “ beautiful crystals.”
The array of crystal hues comes from organic materials — microbes, kidney cells
and the chemicals they produce — trapped within the mineral layers, the team
explains September 13 in Scientific Reports. Bursts of color and different shapes
map a stone’s history, and show that the crystals do dissolve and leave voids that are
then filled by new crystals. Fouke suspects that, like the microbes in Yellowstone’s
hot springs, kidney microbes may jump-start crystal growth. — Aimee Cunningham
Jocelyn Bell Burnell
wins big in physics
Jocelyn Bell Burnell first noticed
the odd, repeating blip in 1967. As a
University of Cambridge graduate
student, she had been reviewing
data from a radio telescope that
she had helped build near campus.
The signal’s source was something
entirely unknown: a pulsar, or a
rapidly spinning stellar corpse that
sweeps beams of radio waves across
the sky like a lighthouse. Her pulsar
find revolutionized astrophysics
and led to the 1974 Nobel Prize in physics — from which she was
famously excluded. Now age 75, Bell Burnell received the Special
Breakthrough Prize in Fundamental Physics on September 6.
Latest tally of human genes
She is donating the $3 million prize money to create scholarships for underrepresented minorities. — Lisa Grossman
SN: What have pulsars taught us?
Bell Burnell: We’ve learned a lot about extreme physics,
because pulsars are really, really extreme. They’re about 10
miles [or 16 kilometers] across, but they weigh as much as
the sun, a thousand million million million million tons. Very
small, very heavy, very peculiar composition. We’re using pulsars to test some of [Albert] Einstein’s theories. His ideas are
standing up very well (SN: 2/3/18, p. 7). And we’re developing
ideas ... for using these things as navigation beacons, when we
start traveling through the galaxy in spaceships.
SN: Why donate the money to diversity initiatives?
Bell Burnell: Diverse bodies are often more successful, more
flexible, more robust. I’d like to see more diversity in science,
and I’d like more people who often don’t get the chance to do
research given the chance.