Description
Male house mice (mus musculus) excrete large quantities of proteins, known as major urinary proteins (MUPs), in their urine. Few studies have directly addressed to what extent MUPs are an honest signal of an individual?s health. We assessed this relationship by measuring the effects infection (a high energy cost) had on urinary MUPs concentration. BALB/c and wild-derived male mice were infected with either a low or high virulence strain of Friend Virus Complex (FVC). Their MUPs concentration were analyzed before infection, during infection and post infection. Virulence was measured using spleen mass as FVC causes splenomegaly. Initial results showed no change in MUPs levels over the course of infection with an average protein-creatinine ratio between 15 and 17 mg/ml at each time point. This is likely due to both strains in actuality being low virulent strains, as only an approximately 50% increase in spleen mass was observed in infected individuals. The experiment was repeated with a more virulent virus strain. Results indicate that mice do significantly lower MUPs levels when faced with infection; MUPs went from 53.04 ± 9.61 mg/ml (pre-time point) to 47.88 mg/ml (post-time point) representing an approximately 11% decrease. This is likely because they need to divert the energy typically allocated to MUPs to fighting off an infection. However, the slopes of decrease between the infected and control mice were not significantly different, thus additional studies need to be performed in a semi-natural habitat, under social competition, where mice will experience more natural stressors.
The Impact of Infectious Disease on Costly Social Signals
Male house mice (mus musculus) excrete large quantities of proteins, known as major urinary proteins (MUPs), in their urine. Few studies have directly addressed to what extent MUPs are an honest signal of an individual?s health. We assessed this relationship by measuring the effects infection (a high energy cost) had on urinary MUPs concentration. BALB/c and wild-derived male mice were infected with either a low or high virulence strain of Friend Virus Complex (FVC). Their MUPs concentration were analyzed before infection, during infection and post infection. Virulence was measured using spleen mass as FVC causes splenomegaly. Initial results showed no change in MUPs levels over the course of infection with an average protein-creatinine ratio between 15 and 17 mg/ml at each time point. This is likely due to both strains in actuality being low virulent strains, as only an approximately 50% increase in spleen mass was observed in infected individuals. The experiment was repeated with a more virulent virus strain. Results indicate that mice do significantly lower MUPs levels when faced with infection; MUPs went from 53.04 ± 9.61 mg/ml (pre-time point) to 47.88 mg/ml (post-time point) representing an approximately 11% decrease. This is likely because they need to divert the energy typically allocated to MUPs to fighting off an infection. However, the slopes of decrease between the infected and control mice were not significantly different, thus additional studies need to be performed in a semi-natural habitat, under social competition, where mice will experience more natural stressors.