Microscopic Resilience: Lessons from the Tardigrade

In our quest to safeguard life on Earth, scientists at the Smithsonian's National Zoo and Conservation Biology Institute (NZCBI) are turning to the tiny yet mighty tardigrade for inspiration. These small creatures, also known as "water bears," are challenging our understanding of survival with their remarkable resilience to extreme conditions.

When you want to preserve something fresh so it lasts longer, you put it in the freezer. Similarly, scientists use cryopreservation to halt the biological clocks of cells, sperm and eggs of threatened or endangered species to store them long-term. This method, while effective, relies heavily on ultra-low temperatures and sophisticated equipment to maintain the viability of these precious genetic materials. But if the freezers containing those biological specimens fail or the temperatures fluctuate, these valuable materials could be lost.

Enter the tardigrade, a creature less than half a millimeter in size but capable of surviving a variety of inhospitable environments. From the freezing void of space to the scorching heat of volcanic vents, tardigrades are able to enter a dry state of suspended animation, reducing their bodily water content to near zero. They do this through a unique gene that produces sugars and proteins within their own cells, allowing them to sustain dramatic water loss (>90%). This remarkable resilience to extreme conditions is guiding innovative conservation methods that could transform the future of endangered species preservation.

By replicating this method of dehydrating cells, researchers can potentially bypass the need for costly and energy-intensive freezing processes, storing biological materials at ambient temperatures with less risk and lower costs. While mammalian oocyte (egg) freezing is already used in many applications—such as human reproductive medicine, farm animal reproduction, and wildlife conservation—little is known about oocyte dehydration and storage at ambient temperatures. Smithsonian NZCBI scientists are making significant advances in exploring dehydration as a new way to preserve the genetic material of endangered species. Their research already shows potential, particularly through the successful partial dehydration and storage of mammalian oocytes. This breakthrough opens up new opportunities in the fields of conservation and reproductive biology, all thanks to the tardigrade.

The journey into dehydration techniques for preservation is just beginning, but the future looks bright (and dry)! Armed with modern tools of genomics and metabolomics, scientists are leveraging the secrets of tardigrades and other extremophiles, discovering traits that could redefine our approach to biodiversity preservation. And with an estimated 90% of biodiversity still to be discovered, the quest for solutions to preserve life on our planet has never been more critical. This research not only expands our toolkit for conserving endangered species but also deepens our understanding of how other organisms demonstrate resilience and adapt to extreme environments.