<i>A. Longum</i> Undergoing Sporulation (IMAGE) California Institute of Technology Caption This colored electron cryotomogram shows Acetonema longum during sporulation. The mother cell has engulfed the daughter, which will become a spore. Inner membranes are shown in red, cell walls are shaded green, and outer membranes appear in blue. When the spore germinates and outgrows, one of its inner membranes will invert and convert into an outer membrane. Credit Cell/Everett Kane/Elitza Tocheva, Dylan Morris & Grant Jensen Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.