Banca de DEFESA: VICTORIA SILVESTRE BORIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VICTORIA SILVESTRE BORIO
DATE: 13/10/2022
TIME: 09:00
LOCAL: Online pela plataforma Google Meet
TITLE:

Effect of dopamine activity inhibition on the immune response of Rhipicephalus microplus inoculated with Metarhizium anisopliae

KEY WORDS:

Hemocytes, biological control, antagonist, ticks, entomopathogenic fungi

PAGES: 52
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Dopamine (DA) is a biogenic monoamine that modulates ticks and insect hemocytes related to the immune system of these arthropods. However, the detailed role of DA in the immune response of ticks is yet to be elucidated. The present study analyzed the effect of a DA receptor antagonist when ticks were challenged with the entomopathogenic fungus Metarhizium anisopliae. Our study evaluated the survival and biologic parameters of Rhipicephalus microplus, its hemolymph’s phenoloxidase activity, the hemocytes’ phagocytic index, DA detection in the hemocytes, and hemocyte quantification. Seven groups were formed as follow: control ticks (CTR), ticks inoculated with phosphate buffer (PBS), inoculated with antagonist 1ɳM (SCH A), 1μM (SCH B), M. anisopliae conidia (MA) and associations (SCH A + MA and SCH B + MA). There was a reduction in survival comparing the means of MA (7 days), with SCH A + MA (5 ½ days; P=0.0253) and SCH B + MA (4 ½ days; P=0.0291). The egg production index (IPO) was lower in the SCH A + MA (9.6%) and SCH B + MA (8.9%) compared to CTR (49.7%; P<0.0001) and the MA (25.1%) (P=0.0098; P=<0.01). The phagocytic index observed in ticks treated with Metarhizium alone was 57.3% in contrast to 18.1% (SCH A+MA) (P<0.0001) and 25.3% (SCH B+MA) (P<0. 0001). No changes in phenoloxidase activity and DA levels in R. microplushemocytes were detected in the presence of the antagonist. The quantification of hemocytes treated with antagonist associated or not with the fungus was similar. This result supports the hypothesis that DA is crucial in the tick defense process, changing the phagocytic capacity of hemocytes and the susceptibility of ticks to infection by entomopathogenic fungi.

BANKING MEMBERS:
Presidente - 2221855 - PATRICIA SILVA GOLO
Interna - 2860277 - ISABELE DA COSTA ANGELO
Externa à Instituição - DIVA DENELLE SPADACCI MORENA
Externo à Instituição - CAIO MÁRCIO DE OLIVEIRA MONTEIRO - UFG
Externa à Instituição - MARIANA GUEDES CAMARGO - UFRRJ