Publications [#44324] of Christine M. Drea

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Papers Published

  1. Drea, C.M., Weldele, M.L., Forger, N.G., Coscia, E.M., Frank, L.G., Licht, P., & Glickman, S.E., Androgens and masculinization of genitalia in the spotted hyaena (Crocuta crocuta). 2. Effects of prenatal anti-androgens, Journal of Reproduction & Fertility, vol. 113 (1998), pp. 117-127 [doi] .
    (last updated on 2011/04/22)

    Abstract:
    To interfere with the unusually masculine ‘phallic’ development that characterizes female spotted hyaenas, pregnant hyaenas were treated with anti-androgens. Effects on genital morphology and plasma androgen concentrations of infants were studied during the first 6 months of life. Although there were consistent ‘feminizing’ effects of prenatal anti-androgen treatment on genital morphology in both sexes, such exposure did not produce males with extreme hypospadia, as it does in other species, nor did it produce females with a ‘typical’ mammalian clitoris and external vagina. ‘Feminization’ of males resulted in a penis with the morphological features of the hyaena clitoris, and ‘feminization’ of females exaggerated the sex differences that are typical of this species. Effects of treatment were present at birth and persisted for at least six months. Flutamide and finasteride treatment of pregnant females also markedly reduced circulating concentrations of testosterone and dihydrotestosterone in maternal plasma during pregnancy. In the infants of treated mothers, plasma ?4 androstenedione was reduced in daughters, but not sons, consistent with an epigenetic hypothesis previously advanced to explain hormonal ‘masculinization’ of females. The present ‘feminizing’ effects of prenatal anti- androgen treatment are consistent with contemporary understanding of sexual differentiation, that accounts for morphological variation between the sexes in terms of steroids. However, current theory does not account for the basic genital structure of females and our data suggest that development of the male penis and scrotum, and the female clitoris and pseudoscrotum, in the spotted hyaena may involve both androgen-dependent and androgen-independent components.