Banca de DEFESA: IANNE CAROLINE DA SILVA NOBRE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : IANNE CAROLINE DA SILVA NOBRE
DATE: 27/02/2023
TIME: 09:00
LOCAL: Recife
TITLE:

VALIDATION OF GENES INVOLVED IN LADYBUG Eriopis connexa (GERMAR) REPRODUCTION BY RNAi

KEY WORDS:

Coleoptera, Coccinelliade, vitellogenin, vitellogenin receptor, dsNRA, siRNA, gene expression.

PAGES: 73
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

Insect reproduction is dependent on developing oocytes synthesizing and absorbing vitellogenin, a process known as vitellogenesis. Vitellogenins (Vg) are glycolipoproteins that are primarily synthesized in fatty body cells and undergo a series of transformations before being excreted in the hemolymph and internalized in the oocytes. VgRs are oocyte membrane proteins that are responsible for the internalization of Vg, and their presence in the ovaries is required for female reproduction. Many insect Vg and VgR genes have already been identified, characterized, and functionally validated using RNA interference (RNAi). Because RNAi allows for the inference of gene function from the phenotype produced by silencing, this technique can be used to unravel the function of Vg and VgR and other genes in natural enemies such as ladybirds, paving the way for the development of methodologies that can preserve or even rear them on a large scale for field release. Interestingly, nutritional factors have a strong influence on the expression of Vg and VgR, as they regulate both the nutrition signaling pathways and the hormone synthesis pathways required for their expression. Therefore, the purpose of this study was to identify and functionally validate Vgs and VgR of Eriopis connexa (Germar) (Coleoptera: Curculionidae) by RNAi, a predatory ladybug that primarily controls aphids, as well as to investigate the effect of preferential feeding on the expression of reproductive genes in this species. As a result, two Vgs genes and one VgR gene were discovered and characterized. Vg expression rates appear to be influenced by food type. Furthermore, experimental conditions for injecting dsRNA into insect hemolymph were established. RNAi-mediated gene silencing revealed that, unlike in other species, these genes knockdown have no effect on oviposition but are critical for egg viability in E. connexa. Furthermore, the two vitellogenin genes appear to be redundant, as both must be silenced to affect egg viability.

COMMITTEE MEMBERS:
Presidente - ***.976.374-** - MARCELO HENRIQUE SANTOS PAIVA - UFRPE
Interno - ***.976.374-** - MARCELO HENRIQUE SANTOS PAIVA - UFPE
Externo à Instituição - VALDIR DE QUEIROZ BALBINO - UFPE