Cover photograph (Copyright © 2007, American Society for Microbiology. All Rights Reserved.): Ascospores of the fungus Talaromyces macrosporus are packed in asci that contain eight spores each. The matured spores are loosely connected by the remnants of the ascus. The spores were cut by a diamond knife and then observed in a frozen state in a scanning electron microscope. The very thick cell wall of the spore is visible in the upper spore. Cell organelles show hardly any detail, which suggests that the cytoplasm is very dense. In fact, these spores belong to the most resilient eukaryotic cells ever reported and can easily survive temperatures of 85°C. (See related article on page 157.)