Original Article
Heredity (1998) 81, 87–91; doi:10.1046/j.1365-2540.1998.00357.x
Sex ratio distortion in Acraea encedon (Lepidoptera: Nymphalidae) is caused by a male-killing bacterium
Francis M Jiggins1, Gregory D D Hurst2 and Michael E N Majerus1
- 1Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH
- 2Department of Biology, Wolfson House, 4 Stephenson Way, London NW1 2HE, UK
Correspondence: Francis M Jiggins, E-mail: fmj1001@mole.bio.cam.ac.uk
Received 24 October 1997; Accepted 4 December 1997.
Abstract
Females of the butterfly Acraea encedon produce either entirely female offspring or males and females in an almost 1:1 sex ratio. The sex ratio produced is maternally inherited and was previously attributed to sex chromosome meiotic drive. We report that all-female lineages are associated with low egg-hatching rates and that the trait is cured by antibiotic treatment. We thus reject the hypothesis that this sex ratio bias is caused by a meiotically driven sex chromosome and, instead, propose that it is associated with a maternally inherited bacterium that kills males.
Keywords:
Acraea encedon, male killing, meiotic drive, sex ratio
