The Effect of Sex-Accessory Gland Removal on Strange-Male-Induced Pregnancy Disruptions in Mice

Abstract

<p> Early pregnancy in mammals can be disrupted by numerous stimuli. In particular, exposure to males which did not sire the litter disrupts early pregnancy in previously inseminated female mice. This is known as the Bruce effect. Evidence suggests that this effect is mediated by chemical emissions (pheromones) from the males. Castration of the males eliminates the effect whereas testosterone replacement restores it. This has suggested that androgen-dependent male accessory glands might be responsible. In particular, the preputial, vesicular and coagulating glands seem likely candidates for subserving the Bruce effect since they have been implicated in a variety of social behaviors.</p> <p> In these experiments, inseminated females were each housed below either 1) two males which had undergone preputial gland removal or, 2) two males which had undergone vesicular-coagulating gland removal or, 3) two males which had undergone preputial, vesicular and coagulating gland removal or 4) two males which had undergone sham surgery. In each case, males which had undergone gland removal disrupted pregnancy in inseminated females to the same extent as did intact males. Histology showed no regeneration of the glands. These results suggest that none of these major androgen-dependent male accessory glands is responsible for pheromonal emissions involved in the Bruce effect.</p>