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Publications [#44317] of Christine Drea

Refereed Publications

1. Drea, C.M., Place, N.J., Weldele, M.L., Coscia, E.M., Licht, P. & Glickman, S.E., Exposure to naturally circulating androgens during foetal life incurs direct reproductive costs in female spotted hyenas, but is prerequisite for male mating, in Proceedings of the Royal Society of London, B, vol. 269 (2002), pp. 1981-1987
   (last updated on 2008/01/02)

   Abstract:
   Among all extant mammals, only the female spotted hyaena (Crocuta crocuta) mates and gives birth through the tip of a peniform clitoris. Clitoral morphology is modulated by foetal exposure to endogenous, maternal androgens. First births through this organ are prolonged and remarkably difficult, often causing death in neonates. Additionally, mating poses a mechanical challenge for males, as they must reach an anterior position on the female’s abdomen and then achieve entry at the site of the retracted clitoris. Here we report that interfering with the actions of androgens prenatally permanently modifies hyaena urogenital anatomy, facilitating subsequent parturition in nulliparous females who, thereby, produce live cubs. By contrast, comparable, permanent anatomical changes in males probably preclude reproduction, as exposure to prenatal anti-androgens produces a penis that is too short and has the wrong shape necessary for insertion during copulation. These data demonstrate that the reproductive costs of clitoral delivery result from exposure of the female foetus to naturally circulating androgens. Moreover, the same androgens that render an extremely unusual and laborious process even more reproductively costly in the female are apparently essential to the male’s physical ability to reproduce with a normally masculinized female.

   Keywords:
   masculinization; androgen; sexual differentiation; reproductive success; spotted hyaena