Frequent and asymmetric cell division in endosymbiotic bacteria of cockroaches.

Many insects are obligatorily associated with and dependent on specific microbial species as essential mutualistic partners. In the host insects, such microbial mutualists are usually maintained in specialized cells or organs, called bacteriocytes or symbiotic organs. Hence, potentially exponential microbial growth cannot be realized but must be strongly constrained by spatial and resource limitations within the host cells or tissues. How such endosymbiotic bacteria grow, divide, and proliferate is important for understanding the interactions and dynamics underpinning intimate host-microbe symbiotic associations. Here we report that