Originally published as Genetics Published Articles Ahead of Print on June 18, 2008.

Genetics, Vol. 179, 1337-1343, July 2008, Copyright © 2008
doi:10.1534/genetics.108.087270

Four Quantitative Trait Loci That Influence Worker Sterility in the Honeybee (Apis mellifera)

Peter R. Oxley1, Graham J. Thompson2 and Benjamin P. Oldroyd

Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia

1 Corresponding author: School of Biological Sciences, Macleay Bldg. A12, University of Sydney, NSW 2006, Australia.
E-mail: peter.oxley{at}usyd.edu.au

The all-female worker caste of the honeybee (Apis mellifera) is effectively barren in that workers refrain from laying eggs in the presence of a fecund queen. The mechanism by which workers switch off their ovaries in queenright colonies is pheromonally cued, but there is genetically based variation among individuals: some workers have high thresholds for ovary activation, while for others the response threshold is lower. Genetic variation for threshold response by workers to ovary-suppressing cues is most evident in "anarchist" colonies in which mutant patrilines have a proportion of workers that activate their ovaries and lay eggs, despite the presence of a queen. In this study we use a selected anarchist line to create a backcross queenright colony that segregated for high and low levels of ovary activation. We used 191 informative microsatellite loci, covering all 16 linkage groups to identify QTL for ovary activation and test the hypothesis that anarchy is recessively inherited. We reject this hypothesis, but identify four QTL that together explain ~25% of the phenotypic variance for ovary activation in our mapping population. They provide the first molecular evidence for the existence of quantitative loci that influence selfish cheating behavior in a social animal.


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Genetics 2008 179: NP. [Full Text]