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tion was to kill the project. agency focuses on the sci- these days. Just last week, The red planet already is other Mars mission Monday
astronaut Scott Kelly com- teeming with active space- from Kazakhstan — an or-
John Grunsfeld, head of ence instrument itself. pleted a 340-day mission craft, including NASA’s biter for measuring atmo-
at the International Space Opportunity and Curiosity spheric gases and a lander
NASA’s science mission di- “The quest to understand Station that’s considered a rovers on the surface, and collectively known as Exo-
scientific steppingstone for Odyssey, Mars Reconnais- Mars 2016.q
rectorate, said the scien- the interior of Mars has
A28tific

SCIENCEand
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Microbe with stripped-down DNA may hint at secrets of life

MALCOLM RITTER an organism that is ... use-
ful,” Hutchison said.
AP Science Writer One goal of such work is
to understand what each
NEW YORK (AP) — Scientists gene in a living cell does,
which would lead to a
have deleted nearly half deep understanding of
how cells work, he said.
the genes of a microbe, With the new bacterium,
“we’re closer to that than
creating a stripped-down we are for any other cell,”
he said. Another goal is
version that still functions, to use such minimal-DNA
microbes as a chassis for
an achievement that adding genes to make the
organisms produce medi-
might reveal secrets of cines, fuels and other sub-
stances for uses like nutri-
how life works. tion and agriculture, said
study co-author Daniel
It may also help research- Gibson of Synthetic Ge-
nomics.
ers create new bacteria The work began with a
manmade version of a mi-
tailored for making medi- crobe that normally lives
in sheep, called M. my-
cines and other valuable coides (my-KOY’-deez). It
has about 900 genes. The
substances. scientists identified 428
nonessential genes, built
The newly created bac- their new genome without
them, and showed that it
terium has a smaller ge- was complete enough to
let a bacterium survive.
netic code than does any Experts not involved with
the work were impressed.
natural free-living coun- “I find this paper really
groundbreaking,” said
terpart, with 531,000 DNA Jorg Stulke of the University
of Goettingen in Germany,
building blocks containing who is working on a simi-
lar project with a different
473 genes. (Humans have bacterium. In an email, he
said the researchers seem
more than 3 billion build- to have gotten at least
very close to a minimum
ing blocks and more than genome for M. mycoides.

20,000 genes).

But even this stripped-

down organism is full of

mystery. Scientists say they

have little to no idea what

a third of its genes actually

do. “We’re showing how

complex life is, even in the

simplest of organisms,” re-

searcher J. Craig Venter

told reporters. “These find- This photo provided by National Center for Imaging and Microscopy Research at the University
ings are very humbling.” of California at San Diego shows Electron micrographs of clusters of JCVI-Syn 3.0 cells magnified
Some of the mystery genes about 15,000 times.
may be clues to discover-
Associated Press

ing unknown fundamental journal Science. ers had pared DNA from And the new genome in-

processes of life, his col- The DNA code, or genome, a different bacterium they cludes genes that are not

league Clyde Hutchison III is contained in a brand- would probably have end- absolutely essential to life,

said in an interview. Both new bacterium dubbed ed up with a different set because they help the

researchers, from the J. JCVI-syn3.0. The genome of genes. For another, the bacterial populations grow

Craig Venter Institute, are is not some one-and-on- minimum genome an or- fast enough to be practical

among the authors of a ly minimal set of genes ganism needs depends on for lab work.

A28 SCIENCEpaper on the project re- needed for life itself. For the environment in which it The genome is “as small as
leaseTdhurThsudrsadya1y0 Mbyarcthhe201o6ne thing, if the research- lives. we can get it and still have

NASA salvages Mars mission that should have launched by now

MARCIA DUNN
AP Aerospace Writer