Transgenerational effect of infection in Plasmodium- infected mosquitoes

Abstract

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.

Recent advances in vertebrate and invertebrate transgenerational immunity in the light of ecology and evolution

“…While the literature abounds with evidence of TGIP in vertebrate and invertebrate systems, its existence is not universal. For example in invertebrates, several studies have not found evidence for TGIP (Voordouw et al 2008;Vorburger et al 2008;Linder and Promislow 2009;Pigeault et al 2015), and in some cases even reversed patterns of negative effects of parental immune stimulation on offspring resistance have been shown (Vantaux et al 2014;Littlefair et al 2017). Such cases may also be more common than the literature suggests as a consequence of publication bias against negative results (Møller and Jennions 2001).…”

Disentangling non-specific and specific transgenerational immune priming components in host–parasite interactions

“…Studies of transgenerational effects on disease typically subject the parental environment to food stress, for example, shortage of food or food of lower quality [30,31], crowding [32] or challenge them with live, weakened, or heat-killed parasites [33][34][35]. Thereafter, a variety of traits of the offspring generation are recorded, such as susceptibility to parasites and offspring fecundity, resistance, immunity, and mortality [36][37][38]. The vast majority of studies on transgenerational effects focused on non-specific immune priming [34,35,[39][40][41][42].…”

Nosema ceranae, Fipronil and their combination compromise honey bee reproduction via changes in male physiology

“…Similar impairments have been observed more broadly in wildlife, including vertebrates and invertebrates 7 – 9 . In insects, reproductive disorders induced by environmental stressors can result in fertility decline 10 – 21 , a change in reproductive behavior, such as choice of sexual partner(s) and mating success 22 , 23 , and diverse effects on offspring production and physiology 10 , 24 – 29 .…”