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Somatic sex identity is cell autonomous in the chicken

Nature volume 464, pages 237242 (11 March 2010) | Download Citation


In the mammalian model of sex determination, embryos are considered to be sexually indifferent until the transient action of a sex-determining gene initiates gonadal differentiation. Although this model is thought to apply to all vertebrates, this has yet to be established. Here we have examined three lateral gynandromorph chickens (a rare, naturally occurring phenomenon in which one side of the animal appears male and the other female) to investigate the sex-determining mechanism in birds. These studies demonstrated that gynandromorph birds are genuine male:female chimaeras, and indicated that male and female avian somatic cells may have an inherent sex identity. To test this hypothesis, we transplanted presumptive mesoderm between embryos of reciprocal sexes to generate embryos containing male:female chimaeric gonads. In contrast to the outcome for mammalian mixed-sex chimaeras, in chicken mixed-sex chimaeras the donor cells were excluded from the functional structures of the host gonad. In an example where female tissue was transplanted into a male host, donor cells contributing to the developing testis retained a female identity and expressed a marker of female function. Our study demonstrates that avian somatic cells possess an inherent sex identity and that, in birds, sexual differentiation is substantively cell autonomous.

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This work was supported by DEFRA and BBSRC (BB/E015425/1). We thank G. Miele, G. Robertson, S. Wilson, A. Sherman, M. Hutchison, F. Thomson and R. Mitchell for technical support and for provision of fertilized eggs and embryos. We also thank T. Cannon for donation of gynandromorph bird G1, and R. Field and N. Russell for photography.

Author Contributions D.Z. and D.M. performed transplantation studies, transcriptome screens, Southern analyses and general molecular biology. S.N. performed immunostaining, H.A.M. performed FISH analyses and P.M.H. performed dissections and post-mortem measurements. M.J.M. performed ISH and suggested transplantation strategy and P.D.L. obtained gynandromorph birds. Overall project was conceived by M.C. and H.M.S. M.C. carried out day-to-day supervision and wrote the manuscript. All authors edited the manuscript.

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Author notes

    • D. Zhao
    •  & D. McBride

    These authors contributed equally to this work.


  1. Division of Developmental Biology and,

    • D. Zhao
    • , D. McBride
    • , S. Nandi
    • , M. J. McGrew
    • , H. M. Sang
    •  & M. Clinton
  2. Division of Genetics and Genomics, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9PS, UK

    • P. M. Hocking
  3. Institute of Cell Biology, University of Edinburgh, West Mains Road, Edinburgh EH9 3JR, UK

    • H. A. McQueen
  4. Animal and Poultry Science Department, University of KwaZulu-Natal, Pietermaritzburg, South Africa

    • P. D. Lewis


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Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to M. Clinton.

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