RESUMO
Lutzomyia longipalpis is known as one of the primary insect vectors of visceral leishmaniasis. For such ectothermic organisms, the ambient temperature is a critical life factor. However, the impact of temperature has been ignored in many induced-stress situations of the vector life. Therefore, this study explored the interaction of Lu. longipalpis with temperature by evaluating its behaviour across a thermal gradient, thermographic recordings during blood-feeding on mice, and the gene expression of heat shock proteins (HSP) when insects were exposed to extreme temperature or infected. The results showed that 72 h after blood ingestion, Lu. longipalpis became less active and preferred relatively low temperatures. However, at later stages of blood digestion, females increased their activity and remained at higher temperatures. Real-time imaging showed that the body temperature of females can adjust rapidly to the host and remain constant until the end of blood-feeding. Insects also increased the expression of HSP90(83) during blood-feeding. Our findings suggest that Lu. longipalpis interacts with temperature by using its behaviour to avoid temperature-induced physiological damage during the gonotrophic cycle. However, the expression of certain HSP might be triggered to mitigate thermal stress in situations where a behavioural response is not the best option.
Assuntos
Leishmaniose Visceral , Psychodidae , Feminino , Animais , Camundongos , Leishmaniose Visceral/veterinária , Psychodidae/fisiologia , Temperatura , Insetos VetoresRESUMO
O Lutzomyia longipalpis é o principal vetor da Leishmania infantum, principal agente etiológico da leishmaniose visceral nas Américas. Observações sobre a ecologia do inseto em áreas urbanas sugerem que o ciclo de vida ocorre em microhabitats peridomiciliares ricos em nutrientes orgânicos.