WEBVTT

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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)