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I live in Utah,
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a place known for having
some of the most awe-inspiring
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natural landscapes on this planet.
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It's easy to be overwhelmed
by these amazing views,
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and to be really fascinated by these
sometimes alien-looking formations.
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As a scientist, I love
observing the natural world.
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But as a cell biologist,
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I'm much more interested
in understanding the natural world
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at a much, much smaller scale.
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I'm a molecular animator,
and I work with other researchers
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to create visualizations
of molecules that are so small,
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they're essentially invisible.
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These molecules are smaller
than the wavelength of light,
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which means that we can
never see them directly,
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even with the best light microscopes.
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So how do I create
visualizations of things
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that are so small we can't see them?
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Scientists, like my collaborators,
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can spend their entire
professional careers
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working to understand
one molecular process.
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To do this, they carry out
a series of experiments
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that each can tell us
a small piece of the puzzle.
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One kind of experiment
can tell us about the protein shape,
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while another can tell us
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about what other proteins
it might interact with,
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and another can tell us
about where it can be found in a cell.
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And all of these bits of information
can be used to come up with a hypothesis,
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a story, essentially,
of how a molecule might work.
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My job is to take these ideas
and turn them into an animation.
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This can be tricky,
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because it turns out that molecules
can do some pretty crazy things.
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But these animations
can be incredibly useful for researchers
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to communicate their ideas
of how these molecules work.
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They can also allow us
to see the molecular world
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through their eyes.
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I'd like to show you some animations,
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a brief tour of what I consider to be
some of the natural wonders
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of the molecular world.
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First off, this is an immune cell.
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These kinds of cells need to go
crawling around in our bodies
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in order to find invaders
like pathogenic bacteria.
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This movement is powered
by one of my favorite proteins
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called actin,
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which is part of what's known
as the cytoskeleton.
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Unlike our skeletons,
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actin filaments are constantly
being built and taken apart.
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The actin cytoskeleton plays
incredibly important roles in our cells.
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They allow them to change shape,
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to move around, to adhere to surfaces,
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and also to gobble up bacteria.
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Actin is also involved
in a different kind of movement.
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In our muscle cells, actin structures
form these regular filaments
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that look kind of like fabric.
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When our muscles contract,
these filaments are pulled together
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and they go back
to their original position
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when our muscles relax.
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Other parts of the cytoskeleton,
in this case microtubules,
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are responsible for long-range
transportation.
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They can be thought of
as basically cellular highways
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that are used to move things
from one side of the cell to the other.
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Unlike our roads,
microtubules grow and shrink,
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appearing when they're needed
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and disappearing when their job is done.
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The molecular version of semitrucks
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are proteins aptly named motor proteins,
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that can walk along microtubules,
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dragging sometimes huge cargoes,
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like organelles, behind them.
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This particular motor protein
is known as dynein,
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and its known to be able
to work together in groups
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that almost look, at least to me,
like a chariot of horses.
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As you see, the cell is this incredibly
changing, dynamic place,
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where things are constantly
being built and disassembled.
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But some of these structures
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are harder to take apart
than others, though.
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And special forces need to be brought in
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in order to make sure that structures
are taken apart in a timely manner.
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That job is done in part
by proteins like these.
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These donut-shaped proteins,
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of which there are many types in the cell,
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all seem to act to rip apart structures
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by basically pulling individual proteins
through a central hole.
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When these kinds of proteins
don't work properly,
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the types of proteins
that are supposed to get taken apart
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can sometimes stick together and aggregate
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and that can give rise
to terrible diseases, such as Alzheimer's.
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And now let's take a look at the nucleus,
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which houses our genome
in the form of DNA.
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In all of our cells,
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our DNA is cared for and maintained
by a diverse set of proteins.
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DNA is wound around proteins
called histones,
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which enable cells to pack
large amounts of DNA into our nucleus.
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These machines
are called chromatin remodelers
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and the way they work
is that they basically scoot the DNA
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around these histones
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and they allow new pieces of DNA
to become exposed.
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This DNA can then be recognized
by other machinery.
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In this case, this large molecular machine
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is looking for a segment of DNA
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that tells it it's
at the beginning of a gene.
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Once it finds a segment,
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it basically undergoes
a series of shape changes
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which enables it to bring in
other machinery
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that in turn allows a gene
to get turned on or transcribed.
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This has to be a very
tightly regulated process
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because turning on the wrong gene
at the wrong time
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can have disastrous consequences.
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Scientists are now able
to use protein machines
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to edit genomes.
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I'm sure all of you have heard of CRISPR.
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CRISPR takes advantage
of a protein known as Cas9,
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which can be engineered
to recognize and cut
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a very specific sequence of DNA.
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In this example,
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two Cas9 proteins are being used
to excise a problematic piece of DNA.
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For example, a part of a gene
that may give rise to a disease.
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Cellular machinery is then used
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to basically glue two ends
of the DNA back together.
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As a molecular animator,
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one of my biggest challenges
is visualizing uncertainty.
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All of the animations I've shown to you
represent hypotheses,
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how my collaborators think
a process works,
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based on the best information
that they have.
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But for a lot of molecular processes,
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we're still really at the early stages
of understanding things,
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and there's a lot to learn.
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The truth is
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that these invisible molecular worlds
are vast and largely unexplored.
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To me, these molecular landscapes
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are just as exciting to explore
as a natural world
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that's visible all around us.
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Thank you.
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(Applause)