Mammalian sexual differentiation: lessons from the spotted hyena

@article{Glickman2006MammalianSD,
  title={Mammalian sexual differentiation: lessons from the spotted hyena},
  author={S. Glickman and G. Cunha and C. Drea and A. Conley and N. Place},
  journal={Trends in Endocrinology \& Metabolism},
  year={2006},
  volume={17},
  pages={349-356}
}
Female spotted hyenas (Crocuta crocuta) are the only female mammals that lack an external vaginal opening. Mating and birth take place through a urogenital canal that exits at the tip of a hypertrophied clitoris. This 'masculine' phenotype spurred a search for an alternate source of fetal androgens. Although androstenedione from the maternal ovary is readily metabolized to testosterone by the hyena placenta, formation of the penile clitoris and scrotum appear to be largely androgen independent… Expand
Development of the external genitalia: perspectives from the spotted hyena (Crocuta crocuta).
TLDR
Data is summarized on development of the external genitalia of the spotted hyena to indicate that early formation of the phallus in both males and females is independent of androgens, and that estrogens play a critical role in penile and clitoral development. Expand
Sex and seasonal differences in aggression and steroid secretion in Lemur catta: Are socially dominant females hormonally ‘masculinized’?
  • C. Drea
  • Biology, Medicine
  • Hormones and Behavior
  • 2007
TLDR
Endocrine profiles and social interaction in the ringtailed lemur (Lemur catta), a species characterized by extreme masculinization of the female, are examined to search for a potential source of circulating androgen in adult females and an endocrine correlate of female dominance or its proxy, aggression. Expand
High maternal androstenedione levels during pregnancy in a small precocial mammal with female genital masculinisation
TLDR
For both species plasma levels of androstenedione and testosterone in adults of both sexes, and in females during different stages of pregnancy were determined, indicating that high levels of this androgen may be involved in the differentiation of masculinized genitalia in female. Expand
Morphology of the external genitalia of the adult male and female mice as an endpoint of sex differentiation
TLDR
Previous results from evaluation of "non-traditional" mammals are presented to demonstrate the complex process of sex differentiation that involves not only androgen-dependent processes, but also estrogen-dependent and hormone-independent mechanisms. Expand
High maternal androstenedione levels during pregnancy in a small precocial mammal with female genital masculinisation
TLDR
It is proposed that female genital masculinisation might be a side effect of early exposure to elevated levels of maternal androgens that might be selected for to speed up precocial development. Expand
Development of urogenital system in the Spix cavy: A model for studies on sexual differentiation.
This study documented, for the first time, the morphological patterns of differentiation of male and female genital organs of Spix cavy (Galea spixii) using histological and ultrastructural analyses,Expand
Endocrine correlates of pregnancy in the ring-tailed lemur (Lemur catta): Implications for the masculinization of daughters
  • C. Drea
  • Medicine, Biology
  • Hormones and Behavior
  • 2011
TLDR
Hormonal correlates of prenatal development were assessed to explore the possibility that maternal androgens may shape the masculine morphological and behavioral features of developing female lemurs and confirm that these steroids would reach the developing female and contribute to her masculinization. Expand
External genital morphology of the ring‐tailed lemur (Lemur catta): Females are naturally “masculinized”
TLDR
Those of the female ring‐tailed lemur are characterized as moderately “masculinized,” highlighting certain morphological similarities and differences between ring‐tails lemurs and the most male‐like of female mammals, the spotted hyena, and calling attention to a potential hormonal mechanism of “Masculinization” in female lemur development. Expand
Endocrine Mediators of Masculinization in Female
TLDR
This review addresses the understanding of the mediating mechanisms of morpho logical and behavioral development in both traditional and exceptional mammal species, and the role for sex steroids in female development remains unclear. Expand
Endocrine Mediators of Masculinization in Female Mammals
Most mammal species show traditional patterns of sexual dimorphism (e.g., greater male size and aggression), the proximal mechanism of which involves the male's greater pre- and postnatal exposure toExpand
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TLDR
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TLDR
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TLDR
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