Ecological plasticity to ions concentration determines genetic response and dominance of Anopheles coluzzii larvae in urban coastal habitats of Central Africa

Abstract

In Central Africa, the malaria vector Anopheles coluzzii is predominant in urban and coastal habitats. However, little is known about the environmental factors that may be involved in this process. Here, we performed an analysis of 28 physicochemical characteristics of 59 breeding sites across 5 urban and rural sites in coastal areas of Central Africa. We then modelled the relative frequency of An. coluzzii larvae to these physicochemical parameters in order to investigate environmental patterns. Then, we assessed the expression variation of 10 candidate genes in An. coluzzii, previously incriminated with insecticide resistance and osmoregulation in urban settings. Our results confirmed the ecological plasticity of An. coluzzii larvae to breed in a large range of aquatic conditions and its predominance in breeding sites rich in ions. Gene expression patterns were comparable between urban and rural habitats, suggesting a broad response to ions concentrations of whatever origin. Altogether, An. coluzzii exhibits a plastic response to occupy both coastal and urban habitats. This entails important consequences for malaria control in the context of the rapid urban expansion in Africa in the coming years.

Systematic Review on Diversity and Distribution of Anopheles Species in Gabon: A Fresh Look at the Potential Malaria Vectors and Perspectives

“…This result could be explained by the fact that the studies that provided the greatest number of species in urban areas date back to the colonial period between the 1930s and 1970s [28][29][30][31], during which the level of urbanization of cities was not the same as today [75,76]. In contrast, very recent studies in Libreville [47,51,52,70] and in Port-Gentil [26] and Mouila [45], report only 2-3 species collected. Thus, we believe that additional studies would be necessary for a better assessment of the impact of anthropization on the diversity of Anopheles species found in this environment.…”

“…coluzzii and An. gambiae) [51,80,81]. In particular, the generalist group includes species such as An.…”

Larval sites of the mosquito Aedes aegypti formosus in forest and domestic habitats in Africa and the potential association with oviposition evolution

“…The study found that An . coluzzii can colonize larval habitats with a wide range of physicochemical conditions, likely associated with the species' dominance in urban settings in Africa (Longo‐Pendy et al, 2021 ).…”

Rehydration of the sleeping chironomid, Polypedilum vanderplanki Hinton, 1951 larvae from cryptobiotic state up to full physiological hydration (Diptera: Chironomidae)

“…Three kinds of water differing in ion content were used for the larva rehydration process: distilled water, mineral water “Cisowianka”, and tap water, because there were indications that the influence of some physical and chemical conditions of water on some fly larvae 39 – 41 . Transport across membranes and specific water channels may be dependent on the ion content.…”