Offsprings of lovers better equipped to cope with infections

Offspring from female mice who mated with their preferred male are better able to cope with an experimental infection compared to those of females mated with non-preferred males, a new research has suggested.

To test whether female mate choice enhances the health and disease-resistance of offspring, either through immune resistance, tolerance to infection, or both, researchers led by Dustin Penn tested female house mice's preferences (Mus musculus) for particular males and then experimentally assigned each female to mate with either their preferred or their non-preferred male.

They found that females that mated with their preferred male produced more offspring and were better able to cope with infection (from Salmonella, a common mouse pathogen) compared to offspring sired by non-preferred males.

They were no better at controlling pathogen loads than offspring from non-preferred males, which suggests that the fitness benefits were due to tolerance to infection rather than immune resistance (the ability to control or eliminate pathogens) per se.

The authors suggest that females assess males' overall condition and health rather than immune resistance per se, and for this reason, sexual selection should enhance offspring tolerance, as well as immune resistance to infection.

Penn and others have shown that ability to resist and survive Salmonella infection is influenced by MHC genes and other loci. However, he emphasizes that they still need to determine whether the fitness benefits they found were due to genetics or maternal allocation into preferred offspring, and that either mechanism will be interesting to explore in future studies.

The study has been published in the journal BMC Evolutionary Biology.