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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
gtTohueaelsrseadpraeayirc2po9mlaMnpaserllacinrhge 201bo6feepnlaanelotnagry-stsacniednintigstsgofoarl

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
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