09/30/2016

Achieving Suspended Animation, With Help From the Water Bear

17:38 minutes

From lef to right: Carl Johansson, Ira Flatow, and John Crowe discussing the tardigrade. Credit: Adeline Xu/UC Davis
From left to right: Carl Johansson, Ira Flatow, and John Crowe discussing the tardigrade. Credit: Adeline Xu/UC Davis

Humans can’t live in a world without water. It’s one of the first things we look for in the search for other Earth-like planets. But there are some organisms that aren’t constrained by a need for H20, like the tardigrade, or water bear. When there’s no water around, this micro-animal can enter a type of cryptobiosis, or state of very low metabolic activity, in which it’s preserved in a desiccated “tun” form—sometimes for years—until water is reintroduced.

That peculiar trait captured the interest of John Crowe, a young researcher who in the late 1970s set out to discover how tardigrades persisted for so long in a waterless environment. As a graduate student, Crowe found that the answer lay in trehalos, a sugar that takes the place of water during cryptobiosis to maintain the structure of the cell membranes.

Even though humans aren’t capable of cryptobiosis on their own, the world of modern medicine has taken a page of out the tardigrade playbook. Scientists have discovered a number of real-world applications for trehalos, most notably in preserving vaccines and platelets that can be sent across the globe and reanimated with a drop of water.

A tardigrade (informally known as a waterbear), via Shutterstock
A tardigrade (informally known as a waterbear), via Shutterstock

Crowe, now a professor of molecular and cellular biology emeritus at UC Davis, is joined by Fresno City College biology professor Carl Johansson in this live interview from the Mondavi Center at the University of California, Davis. They join Ira to discuss how curiosity can lead to inspiration, and why cryptobiosis isn’t as easy as it looks.

Special thanks to our musical guests Joe Kye and Brian Chris Rogers.

Segment Guests

John Crowe

John Crowe is a Professor of Molecular and Cellular Biology Emeritus at the University of California, Davis in Davis, California.

Carl Johansson

Carl Johansson is a professor of Biology at Fresno City College in Fresno, California.

Meet the Producer

About Katie Hiler

Katie Hiler is an assistant producer for Science Friday and the proud mother of two cats, Charleigh and Sadie.

  • CP BREST van KEMPEN

    “WATERBEAR DOWN”
    (by the blogger “Miss Prism”)

    I serenade the Tardigrade
    He’s nature’s superhero.
    He can’t be killed by being chilled
    To near absolute zero.
    He’s happy to be dried or fried
    With X-rays or with heat;
    He will my dears, survive for years
    Without a bite to eat.
    He lives in soil, and springs that boil
    And every hostile place
    He’d even thrive in – well, survive –
    The vacuum of space.
    You need a blade or hand-grenade
    To slay the hardy tardigrade.

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