Résumé
Transgenerational effects of infection have a huge potential to influence
the prevalence and intensity of infections in vectors and, by extension,
disease epidemiology. These transgenerational effects may increase the
fitness of offspring through the transfer of protective immune factors.
Alternatively, however, infected mothers may transfer the costs of
infection to their offspring. Although transgenerational immune protection
has been described in a dozen invertebrate species, we still lack a
complete picture of the incidence and importance of transgenerational
effects of infection in most invertebrate groups. The existence of
transgenerational infection effects in mosquito vectors is of particular
interest because of their potential for influencing parasite prevalence
and intensity and, by extension, disease transmission. Here we present
what we believe to be the first study on transgenerational infection
effects in a mosquito vector infected with malaria parasites. The aim of
this experiment was to quantify both the benefits and the costs of having
an infected mother. We find no evidence of transgenerational protection in
response to a Plasmodium infection. Having an infected mother does,
however, entail considerable fecundity costs for the offspring: fecundity
loss is three times higher in infected offspring issued from infected
mothers than in infected offspring issued from uninfected mothers. We
discuss the implications of our results and we call for more studies
looking at transgenerational effects of infection in disease vectors.