Partner choice and fidelity stabilize coevolution in a Cretaceous-age defensive symbiosis
Abstract
Symbiotic microbes are essential for the survival of many multicellular organisms, yet the factors promoting cooperative symbioses remain poorly understood. Three genera of solitary wasps cultivate antibiotic-producing Streptomyces bacteria for defense of their larvae against pathogens. Here we show that the wasp ancestor acquired the protective symbionts from the soil at least 68 million years ago. Although mother-to-offspring symbiont transmission dominates, exchange between unrelated individuals and uptake of opportunistic microorganisms from the environment occasionally occurs. However, experimental infections of female beewolves reveal that the wasps selectively block transmission of nonnative bacteria to their offspring. These findings suggest a previously unknown mechanism to maintain a specific symbiont over long evolutionary timescales and help to explain the persistence of bacterial mutualists in insects.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- April 2014
- DOI:
- 10.1073/pnas.1400457111
- Bibcode:
- 2014PNAS..111.6359K