Negative effect on early post-implantation pregnancy and progesterone levels in mice infected with the intestinal trematode Echinostoma caproni

A study of mate choice in mice with experimental Taenia crassiceps cysticercosis: can males choose?

The detection and avoidance of infected males has been proposed as a component of female mate choice. However, male mate choice and sexual behaviour in the face of infected females have been rarely investigated. Here, we assessed the exact role displayed by each protagonist in mate choice during experimental Taenia crassiceps (Zeder, 1800) Rudolphi, 1810 cysticercosis. Mate choice was studied at two levels: (1) based on animal odour cues, using a two-choice test and (2) during dyadic interactions, using sexual behaviour and courtship analysis, but also ultrasonic vocalization recordings. Our results showed that female BALB/c mice (Mus musculus L., 1758) spent more time investigating odours in the two-choice test than males, but they were also able to repel infected males during dyadic interactions. Males did not display a clear mating choice with female odours, but during dyadic sexual interactions, they showed a significant aggressiveness towards infected females. Males were able to refrain from copulating with infected females. As shown by a number of studies on female mice, males were able to detect, select, and avoid infected females, and thus express a real mate choice. These observations provided an additional support to the sperm/ejaculate cost and male mate-choice hypothesis.

Pregnancy-associated murine protein-1 (PAMP-1) in wild rodents

The presence of pregnancy-associated murine protein-1 (PAMP-1) in a number of wild rodent species was examined using tandem crossed immunoelectrophoresis and anti PAMP-1 antisera raised in rabbits. PAMP-1 is a protein present in female laboratory mice and rats; analogues were readily detected in the following species: Musculus domesticus, M. musculus, Apodemus sylvaticus, A. agrarius, A. flavicollis, and Microtus arvalus. Immunologically, cross-reacting proteins could not be detected in the laboratory hamster and laboratory guinea pig. Maternal PAMP-1 serum levels were recorded throughout pregnancy in the two species of house mouse: M. domesticus and M. musculus. Both proteins exhibited maximum concentration at day 11 of gestation. During early pregnancy, M. domesticus females had significantly higher serum levels than those of M. musculus females.