Female BALB/c Mice Prefer the Odor of Mates Producing Fewer Progeny

Mate choice is the very important part of sexual selection. It is known that free mate choice is to provide the most viable offspring are born. Researches on different animal species found that viability from introduction to sexual maturity is significantly higher in individuals born in crossbreeding in accordance with free behavioral mate choice, compared to that in crossbreeding against the mate choice. Making the choice, the female may rely on visual, vocal or olfactory signals of male. Most of experiments evaluating sexual choice allowing interactions with the animal, making it impossible to determine the specific contribution of each separate signal. Odor play a crucial role in intraspecific communication in rodents. Individuals are able to recognize sex, reproductive status, genotype, and diet and health condition conspecifics by odor. However, very few articles unite olfactory signals from the male to information about his paternal effects. In our research, we mated a male with two females. The number of live embryos, their weight and the weight of fetal placentas evaluated reproductive success of males. Naive females in olfactory tests then evaluated the volatile urine fraction of the males. Male urine samples were also analyzed using chromatography-mass spectrometry analysis. In result, the naive BALB/c females prefer males with low number of fetus in the litter compared to males with high number of fetus in the litter. Instrumental method of analysis approved the opportunity to differentiate between the groups of males. Other pregnancy parameters did not affect naive females’ preference for male urine samples.