Variation in reproductive traits is associated with short anogenital distance in female rats

Abstract

Anogenital distance was used as a biomarker for natural variation in prenatal androgenization of female rats and was associated with individual differences in a suite of reproductive characteristics. Females with short anogenital distances were likely to have first vaginal estrus earlier than females with longer anogenital distances and to have first vaginal estrus on the same day as vaginal opening. In young adulthood, females with short anogenital distances had shorter ovarian cycles and less intense lordosis reflexes in response to manual palpation than those with longer anogenital distances, but only when living individually, not in groups. Taken together, these findings indicate that prenatal androgenization affects reproductive traits throughout the life span.

Developmental toxicity of polychlorinated biphenyls (PCBs): a systematic review of experimental data

“…Higher androgen concentrations are associated with longer AGDs (Vandenbergh and Huggett 1995;Hernandez-Tristan et al 1999). Prenatal differences in androgenisation also modulate social and sexual behaviour in these species and associations between AGD and behavioural parameters have been described (Drickamer et al 1995;Drickamer 1996;Zehr et al 2001).…”

Isolation and the timing of mammary gland development, gonadarche, and ovarian senescence: Implications for mammary tumor burden

“…For example, Sprague-Dawley rats that have a more vigilant temperament than their cage mates die earlier with mammary tumors (Cavigelli, Yee, & McClintock, 2006) as do socially isolated rats (McClintock, Conzen, Gehlert, Masi, & Olopade, 2005). Finally, life-course ovarian function of Sprague-Dawley rats in groups and social isolation has been well-characterized (Gans & McClintock, 1993;LeFevre & McClintock, 1988Zehr, Gans, & McClintock, 2001) suggesting very different hormonal profiles and microenvironments for mammary development and disease, both with age and across social contexts.…”

The onset of puberty in female mice as reflected in urinary steroids and uterine/ovarian mass: interactions of exposure to males, phyto-oestrogen content of diet, and ano-genital distance

“…The presence of adult conspecifics (Vandenbergh 1967(Vandenbergh , 1976, hormonal exposure during gestation (Zehr et al 2001) and diet (Whitten & Naftolin 1992, Thigpen et al 2003, Takashima-Sasaki et al 2006) have all been found to influence the timing of sexual maturity. The present study was designed to explore how the combination of these factors affects reproductive tissue maturation and steroid production in developing female mice through the examination of uterine and ovarian growth, and profiles of urinary oestradiol and progesterone.…”

“…The onset of sexual maturation in females can also be influenced by the hormonal milieu in utero (Clark & Galef 1988, Zehr et al 2001. Testosterone produced by male foetuses in the third week of gestation (Pointis et al 1980) can be passively transferred to adjacent foetuses (Even et al 1992.…”

“…A female foetus located between two male foetuses will be exposed to higher levels of androgens than a female surrounded by two females. Differences in intrauterine position have significant implications for developing females, as those located in between two males reach sexual maturity later (Clark & Galef 1988, Zehr et al 2001 and have later occurrence of vaginal opening (Zielinski & Vandenbergh 1991) and lengthier cycles once oestrus ensues (vom Saal et al 1981). Vandenbergh & Huggett (1995) have suggested the importance of segregating female subjects based on their prior in utero steroid hormone exposure to reduce variation found in many experimental designs.…”