Avaliação de vias metabólicas e composição lipídica do corpo gorduroso de Rhipicephalus microplus infectados por diferentes isolados d de Metarhizium anisopliae sensu lato

Abstract

The fungus Metarhizium anisopliae sensu lato (s.l.) presents as a huge potential for the control of tick populations. Despite the importance of the fat body in arthropods metabolism and the potential of such pathways as targets to block the spread of such pathogens, studies in ticks are still scarce. This study evaluated the lipid composition and activation of ERK and AMPK enzymes in Rhipicephalus microplus fat body after infection with different isolates of the fungus Metarhizium anisopliae sensu lato. The isolates CG 32, GC 112, GC 148, GC 347 and GC 629 were inoculated as viable or non-viable conidia in the ticks. The engorged females were dissected and their fat bodies were collected 24 and 48 hours after infection. The lipid composition was assessed by thin layer chromatography (TLC) and enzyme activation was detected by Western blotting with antibodies against serine phosphorylation, tyrosine phosphorylation, p-AMPK and p-ERK. The study showed increased levels of triacylglycerol 24 and 48 hours and fatty acid after 48 hours post inoculation of viable fungi in the tick's hemocoel. The detection of the active form of ERK was demonstrated only after inoculation of non-viable conidia of all isolates tested. On the other hand, to the phosphorylated AMPK, only the isolate CG 112 was able to activate with viable or non-viable conidia, whereas isolates CG 32 and CG 629 were able to activate only with non-viable conidia. This study provides the first report about changes in important metabolic pathways in ticks infected with entomopathogenic fungi. However, further studies may be necessary for a better elucidation of this interaction.