Present address: University of Sheffield, Department of Animal & Plant Sciences, Western Bank, Sheffield S10 2TN, UK.
Mechanisms and fitness effects of antibacterial defences in a carrion beetle
Article first published online: 12 MAR 2012
© 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology
Journal of Evolutionary Biology
Volume 25, Issue 5, pages 930–937, May 2012
How to Cite
ARCE, A. N., JOHNSTON, P. R., SMISETH, P. T. and ROZEN, D. E. (2012), Mechanisms and fitness effects of antibacterial defences in a carrion beetle. Journal of Evolutionary Biology, 25: 930–937. doi: 10.1111/j.1420-9101.2012.02486.x
- Issue published online: 5 APR 2012
- Article first published online: 12 MAR 2012
- Received 15 December 2011; revised 27 January 2012; accepted 31 January 2012
- Nicrophorus vespilloides;
- parental care
Parents of many species care for their offspring by protecting them from a wide range of environmental hazards, including desiccation, food shortages, predators, competitors, and parasites and pathogens. Currently, little is known about the mechanisms and fitness consequences of parental defences against bacterial pathogens and competitors. Here, we combine approaches from microbiology and behavioural ecology to investigate the role and mechanistic basis of antibacterial secretions applied to carcasses by parents of the burying beetle Nicrophorus vespilloides. This species rears its larvae on vertebrate carcasses, where larvae suffer significant fitness costs due to competition with bacterial decomposers. We first confirm that anal secretions produced by parents are potently bactericidal and that their effects are specific to gram-positive bacteria. Next, we identify the source of bacterial killing as a secreted lysozyme and show that its concentration changes throughout the breeding cycle. Finally, we show that secreted lysozyme is crucial for larval development, increasing survival by nearly two-fold compared to offspring reared in its absence. These results demonstrate for the first time that anal secretions applied to carrion is a form of parental care and expand the mechanistic repertoire of defences used by parent insects to protect dependent offspring from microbial threats.