Credit: S. SHARMA

Proc. Natl Acad. Sci. USA 106, 20210–20215 (2009)

Many animals survive extreme cold by producing 'antifreeze' compounds that inhibit ice growth. The compounds described so far have all been proteins.

Kent Walters at the University of Notre Dame in Indiana and his colleagues have now characterized the first animal antifreeze that contains little or no protein.

They isolated the compound from the darkling beetle Upis ceramboides (pictured), which can withstand temperatures as low as −60° C, allowing it to live in harsh climates like that of Alaska. Analysis showed it to comprise a xylomannan saccharide with a fatty acid component.