Developmental cheating in the social bacterium Myxococcus xanthus

• Published in: Nature (London) Vol. 404; no. 6778; pp. 598 - 601
• Main Authors: Velicer, Gregory J, Kroos, Lee, Lenski, Richard E
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 06.04.2000; Nature Publishing Group
• Subjects: Bacteria; Bacteriology; Biological and medical sciences; Cell Division; Cloning; Evolution; fruit bodies; Fundamental and applied biological sciences. Psychology; Genetics; Genotypes; Growth, nutrition, cell differenciation; Microbiology; Mutation; Myxococcus xanthus; Myxococcus xanthus - genetics; Myxococcus xanthus - growth & development; Myxococcus xanthus - physiology; Natural populations; Social behavior; spores; Spores, Bacterial; Myxococcales; Life cycle; Social behavior; Myxococcus xanthus; Sporulation; Bacteria; Myxococcaceae; Differentiation; Defectivity; Microbial community
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35007066

Cheating is a potential problem in any social system that depends on cooperation and in which actions that benefit a group are costly to individuals that perform them. Genetic mutants that fail to perform a group-beneficial function but that reap the benefits of belonging to the group should have a within-group selective advantage, provided that the mutants are not too common. Here we show that social cheating exists even among prokaryotes. The bacterium Myxococcus xanthus exhibits several social behaviours, including aggregation of cells into spore-producing fruiting bodies during starvation. We examined a number of M. xanthus genotypes that were defective for fruiting-body development, including several lines that evolved for 1,000 generations under asocial conditions and others carrying defined mutations in developmental pathways, to determine whether they behaved as cheaters when mixed with their developmentally proficient progenitor. Clones from several evolved lines and two defined mutants exhibited cheating during development, being over-represented among resulting spores relative to their initial frequency in the mixture. The ease of finding anti-social behaviours suggests that cheaters may be common in natural populations of M. xanthus.