Bruce effect

Odours of unfamiliar male mice may terminate pregnancies, i.e. the Bruce effect.

In order to have evolved and persisted in the population, the Bruce Effect must afford individuals a fitness advantage.

The incidence of the Bruce Effect depends on the timing of pheromone exposure.

The Bruce Effect is most common in polygynous rodent species, for which the risk of infanticide is highest.

Some females abort or resorb their own young while they are still in development after a new male takes over; this is known as the Bruce effect.

These studies further support estradiol's role in mediating the Vandenbergh effect (as well as the Bruce effect).

Androgens and oestrogens, particularly oestradiol (E2), are also crucial chemosignals regulating the Bruce Effect.

The Bruce effect, or pregnancy block, refers to the tendency for female rodents to terminate their pregnancies following exposure to the scent of an unfamiliar male.

Their findings suggested that some aspects of the Vandenbergh effect as well as the Bruce effect may be related to exogenous estradiol from males.

In 1959, she published her discovery of what is now called the Bruce effect, the termination of pregnancy following exposure to the scent of an unfamiliar male.

For instance if a pregnant mouse is exposed to the urine of a 'strange' male during a critical period after coitus then the pregnancy fails (the Bruce effect).

The Bruce Effect can also aid in maintaining social status, with dominant males leaving more urinal scent markings, and so blocking the pregnancies of subordinate males.

The Bruce Effect has also been observed in geladas and it has also been proposed, but not confirmed, in other non-rodent species such as the lion.

The exposure of a recently bred mouse to the pheromones of a strange male mouse may prevent implantation (or pseudopregnancy), a phenomenon known as the Bruce effect.

Also, unlike vasopressin 1b receptor and oxytcoin knockout mice, Avpr1a KO mice have a normal Bruce effect (appropriate failure of pregnancy in presence of novel male).

Hilda Margaret Bruce (5 April 1903 - 2 November 1974) was a British zoologist, best known for her discovery of the Bruce effect, a pheromonal behaviour observed in many rodent species.

Spontaneous abortion occurs in pregnant Prairie Voles when their mate is removed and they are exposed to a new male, an example of the Bruce effect, although this effect is seen less in wild populations than in the laboratory.

This is a phenomenon observed by Wesley K. Whitten (1956, 1966, 1968), whereby male mouse pheromone-laden urine synchronizes the estrus cycle "among unisexually grouped females," and is an example of male-to-female pheromonal effects in mice, similar to the Bruce effect.