Does multiple paternity influence offspring disease resistance?

Abstract

It has been suggested that polyandry allows females to increase offspring genetic diversity and reduce the prevalence and susceptibility of their offspring to infectious diseases. We tested this hypothesis in wild‐derived house mice (Mus musculus) by experimentally infecting the offspring from 15 single‐ and 15 multiple‐sired litters with two different strains of a mouse pathogen (Salmonella Typhimurium) and compared their ability to control infection. We found a high variation in individual infection resistance (measured with pathogen loads) and significant differences among families, suggesting genetic effects on Salmonella resistance, but we found no difference in prevalence or infection resistance between single‐ vs. multiple‐sired litters. We found a significant sex difference in infection resistance, but surprisingly, males were more resistant to infection than females. Also, infection resistance was correlated with weight loss during infection, although only for females, indicating that susceptibility to infection had more harmful health consequences for females than for males. To our knowledge, our findings provide the first evidence for sex‐dependent resistance to Salmonella infection in house mice. Our results do not support the hypothesis that multiple‐sired litters are more likely to survive infection than single‐sired litters; however, as we explain, additional studies are required before ruling out this hypothesis.

On the saliva proteome of the Eastern European house mouse (Mus musculus musculus) focusing on sexual signalling and immunity

“…It is possible that various antimicrobial proteins are male biased simply to compensate for the testosterone dependent immunosuppression of reproducing males67. Moreover the sex-dependent resistance against bacteria ( Salmonella typhimurium ) has also been demonstrated in the house mouse where males were more resistant than females68. We have also detected high levels of the prolactin-inducible protein (PIP) which is a submandibular gland protein with the ability to bind immunoglobulin G (IgG), IgG-Fc, CD4-T cell receptor, and different species of bacteria (mainly streptococci), thus playing an important role in non-immune defense69.…”

Direct evidence for increased disease resistance in polyandrous broods exists only in eusocial Hymenoptera

“…Only one publication did not find evidence supporting GDDRH (Table 1 ). The two non-hymenopteran species in the direct studies data set utilized the house mouse ( Mus musculus ) and the western tent caterpillar ( Malacosoma californicum pluviale [ 19 , 72 ]; neither found evidence for decreased disease resistance in polyandrous relative to monandrous broods (Table 1 ).…”

Living with relatives offsets the harm caused by pathogens in natural populations

“…Table S5). For example, in the grey foam-nest tree frog, Chiromantis xerampelina, rates of mortality went up by 22% when average group relatedness increased from 0.25 to 0.5 (Phillip G. Byrne and Whiting, 2011a), whereas in the house mouse, Mus musculus, relatedness of groups had little effect on mortality (Thonhauser et al, 2016). Such variation was ubiquitous across all taxonomic groups and was largely independent of phylogenetic history (% of variation explained by phylogeny = 8.195 (0.107, 31.591).…”

“…When many pathogens are present, groups of related individuals are more likely to be susceptible to at least one pathogen, which can reduce variation in pathogen abundances across groups to a similar level to groups of unrelated individuals (Ganz and Ebert, 2010;van Baalen and Beekman, 2006). While both increases and decreases in variation in rates of parasitism and mortality have been found in specific study species (Ganz and Ebert, 2010;Seeley and Tarpy, 2007;Thonhauser et al, 2016), whether relatedness generally increases or decreases variation in pathogen abundances and mortality across groups remains to be established.…”