Analysis of the Life Cycle of Mycoplasma gallisepticum

Abstract

Morowitz, Harold J. (Yale University, New Haven, Conn.), and Jack Maniloff . Analysis of the life cycle of Mycoplasma gallisepticum . J. Bacteriol. 91: 1638–1644. 1966.—A series of electron microscope observations on Mycoplasma gallisepticum strain A5969 have been made by use of thin-section techniques and negative staining. The methods presented a consistent picture of a postdivision cell, which contains a fibrillar nuclear region, surrounding ribosomal region, highly organized bleb at one end of the cell, granular infrableb region, and bounding unit membrane. Cell division commenced with the appearance of a second infrableb area at the end of the cell opposite the original bleb. A new bleb grew in this area, and the cell then elongated. The nuclear material segregated into two parts separated by a band of ribosomes. A constriction appeared, in this central ribosome-packed area, leading to the formation of two daughter cells. The following was noted: the cells were very small (volume, 5 × 10 −14 cm 3 ); each cell was highly structured and strongly ordered; and the replication appeared to be a very precisely programmed series of events.