An analysis of the structure of the bilaminar lamellae of the hamster egg.

The unfertilized hamster egg contains a ubiquitous distribution of lamellate structures. Normally the lamellae are bilaminar, although occasionally both single sheets and multiple sheets are seen. Detailed analysis of the structure of a single bilaminar lamella shows that each sheet of the two-sheet structure is identical and made up of repeating rhombohedral units whose principal axes are in the ratio of 2:1. Each sheet lies at 90 degrees to the other. Using this information, a single bilaminar lamella has been reconstructed. This reconstruction accounts for its major ultrastructural features.