Experimental parasite infection reveals costs and benefits of paternal effects.
Bottom Line: Forces shaping an individual's phenotype are complex and include transgenerational effects.Whether and when such paternal effects are adaptive, however, remains elusive.Altogether, these results demonstrate that parasite resistance and tolerance are shaped by processes involving both genetic and non-genetic inheritance and suggest a context-dependent adaptive value of paternal effects.
Affiliation: Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, 24306, Germany.Show MeSH
Related in: MedlinePlus
Mentions: All exposed G1 males were infected with at least one parasitic worm. We did not find significant differences in testes mass, total sperm concentration or measures of sperm velocity between exposed and unexposed males (testes mass: P = 0.13; total sperm concentration: P = 0.07; all velocities: P > 0.2). However, motile sperm concentration was found to be significantly lower in exposed males than in unexposed males (F1,122=4.595, P = 0.034; Fig. 1). This difference translated into an advantage for the unexposed G1 males, which fertilised on average 65.65% of the eggs. This value was significantly higher than an evenly shared paternity (td.f.=14 = 2.181, P = 0.023), but not so when total sperm concentration was experimentally matched between brothers (td.f.=13 = 1.003, P = 0.167). These results suggest a reduction in the concentration of motile sperm in response to infection (Pearson's correlation between total and motile sperm concentration: r = 0.908, P < 0.001).
Affiliation: Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, 24306, Germany.