Banca de DEFESA: FRANCISCO RÔMULO OLIVEIRA MAGALHÃES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCISCO RÔMULO OLIVEIRA MAGALHÃES
DATE: 18/04/2024
TIME: 08:30
LOCAL: Híbrido. Presencial: Sala Prof Laerte Grisi no LQEPV e virtual: https://meet.google.com/kub-fjrn-rdz
TITLE:

Influence of Different Nutritional Stages and Herpetomonas muscarum infection in the Redox Metabolism of Stomoxys calcitrans, the stable fly

 

KEY WORDS:

Stomoxys calcitrans; mechanical transmission; NADPH oxidase enzymes; Reactive Oxygen Species; oxidative stress; Herpetomonas muscarum.

PAGES: 110
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUMMARY:

̇Stomoxys calcitrans, commonly known as the stable fly, is a significant mechanical vector that plays a crucial role in the transmission of pathogens in livestock environments, impacting animal health and causing economic losses. Our study focuses on the expression of NADPH oxidases (NOX), enzymes that produce reactive oxygen species (ROS) under certain stimuli, and have various roles in the metabolic activities and redox metabolism of S. calcitrans, under varied nutritional conditions, including fasting, feeding on sucrose, and blood feeding. We also investigated the same parameters following infection with Herpetomonas muscarum, a monoxenous trypanosomatid previously found to naturally infect the fly by our group. The aim of this research is to verify the expression of the NOX enzymes and the modulation of pro- and antioxidant responses in S. calcitrans, particularly in response to different nutritional states and protozoan infection. The adopted methodology encompassed bioinformatic analysis techniques for identification, characterization of NOX isoforms, followed by quantitative gene expression experiments through real-time PCR to measure the levels of NOX in the insect's gut and fat body, as well as redox activities, both pro- and antioxidants. Genes for the NOX5 and DUOX1/2 enzymes were identified from the genome of S. calcitrans, showing homology with those of Drosophila melanogaster and Musca domestica. The results revealed a significant variation in the expression of the NOX enzyme genes in response to the different nutritional states, in addition to a notable increase in NOX5 expression in the fat body after H. muscarum infection. Furthermore, it was observed that the nutritional state directly affects redox activity, modulating both the production of pro-oxidant molecules and the activation of antioxidant responses. Flies in fasting and blood-fed conditions showed an increase in redox activity, indicating a possible adaptive mechanism to deal with oxidative stress. In contrast, sucrose-fed flies exhibited a less intense redox response, suggesting differences in the management of oxidative stress according to the diet. A role of NOX enzymes in regulating the redox metabolism of S. calcitrans is suggested, influencing the insect's ability to respond to nutritional and pathogenic challenges. The modulation of NOX expression and redox activity, investigated for the first time in the present work in S. calcitrans, suggests complex adaptive mechanisms that allow the insect to maintain homeostasis in the face of environmental variations and infections. These findings broaden the understanding of the biology of disease vectors, offering perspectives for the development of vector control strategies that exploit the insect's vulnerability to oxidative stress.

COMMITTEE MEMBERS:
Presidente - 1792175 - PATRICIA FAMPA NEGREIROS LIMA
Interna - 3103528 - CLAUDIA BEZERRA DA SILVA
Externo ao Programa - 1555317 - EMERSON GUEDES PONTES - UFRRJExterno ao Programa - 1109555 - JAIRO PINHEIRO DA SILVA - UFRRJExterna à Instituição - EVELIZE FOLLY DAS CHAGAS - UFF
Externa à Instituição - ANGELA HAMPSHIRE LOPES - UFRJ
Externa à Instituição - SUZETE ARAUJO OLIVEIRA GOMES - UFF