Female Mate Choice in Rodents

Abstract

The selection of suitable mates from a pool of potential candidates is one of the most important choices a female rodent has to make. It influences Darwinian fitness directly via the number of offspring produced but also by its viability, fertility, and fecundity. Numerous mechanisms have evolved to ensure this fitness increase by maximizing reproductive success. They act at various stages – before and/or during copulation, between copulation and fertilization, after fertilization but before parturition, after birth of offspring until weaning – and include both social/behavioral and genetic traits. The former comprise the provision of beneficial services such as food, shelter, defense against harassment by other males, or even parental care. These traits are rather obvious, whereas genetic and biochemical traits are much more difficult to decipher. In addition to behavioral aspects such as mating systems, we discuss in greater detail the functions and impact of genetic loci on mate choice. We cover the t-complex in mice, the major histocompatibility complex including the difficulty of linking its diversity to mate choice, the oxytocin locus and its impact, both the olfactory system and the accessory olfactory system, and recent discoveries such as the ESP-1 locus. Although the amount of data linking genetic and behavioral information is steadily increasing, most data have been gained from just a few rodent species, as the reader will note throughout the chapter. However, with the dawn of next generation sequencing, such gaps will hopefully be closed in the near future.