Masculinized dominant females in a cooperatively breeding species

Authors

  • NADIA AUBIN-HORTH,

    1. Harvard University, Bauer Center for Genomics Research, 7 Divinity Avenue, Cambridge, MA 02138, USA,
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  • JULIE K. DESJARDINS,

    1. McMaster University, Department of Psychology, Neuroscience and Behaviour, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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  • YEHODA M. MARTEI,

    1. Harvard University, Bauer Center for Genomics Research, 7 Divinity Avenue, Cambridge, MA 02138, USA,
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  • SIGAL BALSHINE,

    1. McMaster University, Department of Psychology, Neuroscience and Behaviour, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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  • HANS A. HOFMANN

    1. Harvard University, Bauer Center for Genomics Research, 7 Divinity Avenue, Cambridge, MA 02138, USA,
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    • Present address: University of Texas at Austin, Section of Integrative Biology, Institute for Cellular & Molecular Biology, Institute for Neuroscience, 1 University Station — C0930, Austin, TX 78712, USA.


Nadia Aubin-Horth, Present address: Université de Montréal, Département de Sciences Biologiques, 90 avenue Vincent-D’Indy, Montréal, Québec, Canada H2V 2S9. Fax: 514-343-2293; E-mail: n.aubin-horth@umontreal.ca

Abstract

The molecular mechanisms underlying complex social behaviours such as dominance are largely unknown. Studying the cooperatively breeding African cichlid Neolamprologus pulcher, we show that dominant females were similar to dominant males in dominance behaviour, high testosterone levels and brain arginine vasotocin expression (a neuropeptide involved in vertebrate territorial, reproductive and social behaviours) compared to subordinate helpers, but had lower levels of 11-ketotestosterone than males. Furthermore, brain gene expression profiles of dominant females were most similar to those of the males (independent of social rank). Dominant breeder females are masculinized at the molecular and hormonal level while being at the same time reproductively competent, suggesting a modular organization of molecular and endocrine functions, allowing for sex-specific regulation.

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