Abstract
In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.
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Acknowledgments
We thank Dr. Li Tian (Pennsylvania State University) for his help with photography and members of the Zhou lab for their comments and discussion. This study was supported by William L. and Ruth D. Nutting Student Research Grant from the International Union for the Study of Social Insects (North American Section), Kentucky Opportunity Fellowship from the University of Kentucky to Q.S., and the US Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) Hatch project (accession number 1004654) to X.Z. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors’ and do not necessarily reflect the view of NIFA or USDA. This is publication No. 17-08-002 of the Kentucky Agricultural Experiment Station and is published with the approval of the Director. The granting agencies have no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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Q.S., K.F.H., and X.Z. designed the experiments; Q.S. and J.D.H conducted the experiments; Q.S. and K.F.H analyzed the data; Q.S. wrote the manuscript; and K.F.H and X.Z. revised the manuscript. All authors approved the final manuscript.
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Communicated by: Sven Thatje
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Sun, Q., Haynes, K.F., Hampton, J.D. et al. Sex-specific inhibition and stimulation of worker-reproductive transition in a termite. Sci Nat 104, 79 (2017). https://doi.org/10.1007/s00114-017-1501-5
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DOI: https://doi.org/10.1007/s00114-017-1501-5