The Bruce Effect: An Evaluation of Male/Female Advantages

1979 ◽  
Vol 114 (6) ◽  
pp. 932-938 ◽  
Author(s):  
P. L. Schwagmeyer
Keyword(s):  
Bruce Effect

scholarly journals Excretion and binding of tritium-labelled oestradiol in mice (Mus musculus): implications for the Bruce effect

Reproduction ◽  
2010 ◽  
Vol 139 (1) ◽  
pp. 255-263 ◽  
Author(s):  
Adam C Guzzo ◽  
Robert G Berger ◽  
Denys deCatanzaro
Keyword(s):  
Cerebral Cortex ◽  
Intranasal Administration ◽  
Male Mice ◽  
Olfactory Bulbs ◽  
Tissue Samples ◽  
Mouse Urine ◽  
Osmotic Pumps ◽  
Bruce Effect ◽  
Blastocyst Implantation ◽  
Pre Treatment

Male mouse urine contains 17β-oestradiol (E2) and other steroids. Given that males actively direct urine at proximate females and intrauterine implantation of blastocysts is vulnerable to minute amounts of exogenous oestrogens, males' capacity to disrupt early pregnancy could be mediated by steroids in their urine. When male mice were implanted with osmotic pumps containing tritium-labelled E2 (3H-E2) or injected i.p. with 3H-E2, radioactivity was reliably detected in their urine. Following intranasal administration of 3H-E2 to inseminated females, radioactivity was detected in diverse tissue samples, with there being significantly more in reproductive tissues than in brain tissues. When urine was taken from males injected with 3H-E2, and then intranasally administered to inseminated females, radioactivity was detected in the uterus, olfactory bulbs, and mesencephalon and diencephalon (MC+DC). When inseminated and ovariectomised females were perfused at the point of killing to remove blood from tissues, more radioactivity was detected in the uterus than in muscle, olfactory bulbs, MC+DC and cerebral cortex. Pre-treatment with unlabelled E2 significantly reduced the uptake of 3H-E2 in the uterus. Taken with evidence that males deliver their urine to the nasal area of females, these results indicate that male urinary E2 arrives in tissues, including the uterus, where it could lead to the disruption of blastocyst implantation.

scholarly journals Female behaviour plays a critical role in controlling murine pregnancy block

2009 ◽  
Vol 276 (1662) ◽  
pp. 1723-1729 ◽  
Author(s):  
Stuart D Becker ◽  
Jane L Hurst
Keyword(s):  
Critical Period ◽  
Critical Role ◽  
Reproductive Investment ◽  
Dominant Male ◽  
Critical Periods ◽  
Nest Sites ◽  
Bruce Effect ◽  
Male Scent ◽  
Female Behaviour ◽  
Mated Female

Exposure of recently mated female rodents to unfamiliar male scents during daily prolactin surges results in pregnancy failure (the ‘Bruce effect’). Control of nasal contact with male scents during these narrow windows of sensitivity could allow females to maintain or terminate pregnancy, but female behavioural changes specifically during this critical period have not been investigated. We examined the approach or avoidance of familiar stud strain and unfamiliar male scents by recently mated female mice. Females that maintained pregnancy avoided both unfamiliar and familiar male scent during critical periods of susceptibility for the Bruce effect. By contrast, females that did not maintain pregnancy showed a sharp rise in the time spent with unfamiliar male scent during this critical period. Manipulation of the social status of unfamiliar and stud strain scent donors did not affect the likelihood of pregnancy block, although females spent more time with dominant male scents across all time periods. The ability to control the Bruce effect through behaviour during brief sensitivity just before dusk, when females are likely to be in nest sites, provides a mechanism by which females may adjust their reproductive investment according to nest site social stability and likelihood of offspring survival.

scholarly journals BRUCE EFFECT COMPETENCE IN YELLOW-LETHAL HETEROZYGOUS MICE

Reproduction ◽  
1974 ◽  
Vol 40 (2) ◽  
pp. 483-486 ◽  
Author(s):  
R. KAKIHANA ◽  
L. B. ELLIS ◽  
S. A. GERLING ◽  
S. L. BLUM ◽  
S. KESSLER
Keyword(s):  
Bruce Effect

scholarly journals Male-mediated maturation in a wild primate

2020 ◽  
Author(s):  
Amy Lu ◽  
Jacob A. Feder ◽  
Noah Snyder-Mackler ◽  
Thore J. Bergman ◽  
Jacinta C. Beehner
Keyword(s):  
Head Start ◽  
Fetal Loss ◽  
Father Absence ◽  
Early Puberty ◽  
Immature Female ◽  
Father Presence ◽  
Bruce Effect ◽  
First Case ◽  
Reproductive Male ◽  
Alternative Scenarios

AbstractIn humans, a controversial hypothesis suggests that father absence promotes early puberty in daughters. Data from rodents confirm females accelerate maturation with exposure to novel males (“Vandenbergh effect”) and delay it with exposure to male relatives. Here, we report the first case of male-mediated maturation in a wild primate, geladas (Theropithecus gelada). Females were more likely to mature after a change in the reproductive male: some matured earlier than expected (Vandenbergh effect) and some later (due to father presence). Novel males stimulated a surge in estrogens for all immature females - even females too young to mature. Although male-mediated puberty accelerated first births, the effect was modest, suggesting that alternative scenarios, such as co-evolution with the Bruce effect (male-mediated fetal loss) may explain this phenomenon.One Sentence SummaryNovel males induce an estrogen surge, male-mediated puberty, and a head-start on reproduction for immature female geladas.

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