Unregulated exposure to xenoestrogens such as bisphenol A is now incriminated in the occurrence of cryptorchidism and hypospadias - Possible causes of inconsistencies in prior studies include the use of small samples often fewer than 20, or even 10, participants per groupthe use of measures that do not show substantial sex differences, and the use of inappropriate control groups, or no control group at all.
To what extent fetal programming may determine sexual orientation is also a matter of discussion. Cryptorchidism in mice mutant for InsI3.
Differentiation of the male and female reproductive systems does not occur until the fetal period of development. Women with CAIS do not differ in their sexual orientation from female population norms [ ] or from matched female controls [ 66 ]. Alternative reproductive tactics an integrative approach.
In humans, biological sex is determined by five factors present at birth: the presence or absence of a Y chromosome, the type of gonadsthe sex hormonesthe internal genitalia such as atypical prenatal sex differentiation in language in Odessa uterus in femalesand the external genitalia.
The influence of gonadectomy, androgen exposure, or a gonadal graft in the neonatal rat on the volume of the sexually dimorphic nucleus of the preoptic area. In addition, women might not have felt sufficiently comfortable to reveal their sexual orientation.
If more of the testosterone these men produce is converted to DHT in the periphery, less could be available for conversion to estradiol in the brain, thus leading to greater masculinization of the external genitalia, but reduced neurobehavioral masculinization.
Brain Research. More articles related to sexual differentiation. After they failed to demonstrate mutations in known steroidogenic enzymes, they explored genes acting in the alternate pathway of androgen synthesis. The mechanism of androgenic action on the gubernaculum is controversial.
Requirement for Lim1 in head-organizer function. Under physiological conditions in the XY gonad, the upregulation of SRY induces a destabilization of that balance, initiating the testis cascade.
SRY has lost much of its prestige because it has a very weak transactivation potential, is expressed very transiently in the mouse, weakly at best in other mammals and not at all in sub-mammalian species reviewed in ref. Author manuscript; available in PMC Mar 7.
SF1 also plays an important role in spermatogenesis, Leydig cell function, ovarian follicle development and ovulation, as demonstrated by a gonad-specific disruption of SF1 Males scored higher than females on dominance and on physical aggression and lower than females on tender-mindedness and interest in infants.
Female puberty and its disorders.