Social status does not predict responses to Seoul virus infection or reproductive success among male Norway rats

Abstract

Trade-offs exist among life history strategies that are used to increase survival and reproduction; such that, males that engage in more competitive behaviors may be more susceptible to infection. Hantaviruses are transmitted horizontally between rodents through the passage of virus in saliva during wounding and male rodents are more likely to be infected with hantaviruses than females. To determine whether a trade-off exists between dominance and susceptibility to Seoul virus infection, male Long Evans rats were group housed (3/cage) with a female rat and aggressive and subordinate behaviors were monitored during a 10 day group housing condition. After behavioral testing, males were individually housed, inoculated with Seoul virus, and blood, saliva, and fecal samples were collected. Dominant males initiated more aggressive encounters than subordinate males. Dominant and subordinate males, however, had similar steroid hormone concentrations, anti-Seoul virus IgG responses, and weight gain over the course of infection. A similar proportion of dominant and subordinate males shed virus in saliva and feces during infection. Using microsatellite DNA markers paternity was assigned to pups derived during the group housing period. In contrast to our initial hypothesis, dominant and subordinate males sired a similar percentage of pups. Taken together, host social status may not predict reproductive success or susceptibility to hantaviruses in rodent reservoir populations.

Sociosexual behaviors and reproductive success of rats (Rattus norvegicus) in a seminatural environment

“…Likewise, dominance did not affect the males' fertility. Similar results have been reported previously [38,39]. Considering that wild rats rarely compete for access to females [1,40], there is not much reason to expect dominance to have much influence on fertility.…”

Urban population genetics of slum‐dwelling rats (Rattus norvegicus) in Salvador, Brazil

“…; Hinson et al . ). The influx of new genes would be amplified by the high fecundity and short generation time typical of this species.…”

The costs of dominance: testosterone, cortisol and intestinal parasites in wild male chimpanzees

“…Dominance status was also unrelated to anti-Seoul virus IgG responses in inoculated male Norway rats ( Rattus norvegicus ) [108]. …”