Blood-feeding induces reversible functional changes in flight muscle mitochondria of Aedes aegypti mosquito.
BACKGROUND
Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energy-transducing pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism. Therefore, regulation of mitochondrial function should be relevant for hematophagous arthropods. Here, we investigated the effects of blood-feeding on flight muscle (FM) mitochondria from the mosquito Aedes aegypti, a vector of dengue and yellow fever.


RESULTS
Blood-feeding caused a reversible reduction in mitochondrial oxygen consumption, an event that was parallel to blood digestion. These changes were most intense at 24 h after blood meal (ABM), the peak of blood digestion, when oxygen consumption was inhibited by 68%. Cytochromes c and a+a(3) levels and cytochrome c oxidase activity of the electron transport chain were all reduced at 24 h ABM. Ultrastructural and molecular analyses of FM revealed that mitochondria fuse upon blood meal, a condition related to reduced ROS generation. Consistently, BF induced a reversible decrease in mitochondrial H(2)O(2) formation during blood digestion, reaching their lowest values at 24 h ABM where a reduction of 51% was observed.


CONCLUSIONS
Blood-feeding triggers functional and structural changes in hematophagous insect mitochondria, which may represent an important adaptation to blood feeding.
Gonçalves
Renata L S
RL
Laboratório de Bioquímica Redox, Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
Machado
Ana Carolina L
AC
Paiva-Silva
Gabriela O
GO
Sorgine
Marcos H F
MH
Momoli
Marisa M
MM
Oliveira
Jose Henrique M
JH
Vannier-Santos
Marcos A
MA
Galina
Antonio
A
Oliveira
Pedro L
PL
Oliveira
Marcus F
MF
D000330:Aedes / Q000378:metabolism / Q000502:physiology*; D000821:Animal Feed; D053180:Animal Nutrition Sciences; D000818:Animals; D001769:Blood / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005426:Flight, Animal; D006861:Hydrogen Peroxide / Q000737:chemistry; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008931:Mitochondria, Muscle / Q000378:metabolism*; D008954:Models, Biological; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D012313:RNA / Q000378:metabolism; D011817:Rabbits; D017382:Reactive Oxygen Species; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017382:Reactive Oxygen Species; D012313:RNA; D006861:Hydrogen Peroxide; D003576:Electron Transport Complex IV