Silencing of RpATG8 impairs the biogenesis of maternal autophagosomes in vitellogenic oocytes, but does not interrupt follicular atresia in the insect vector < i > Rhodnius prolixus < /i >

by J éssica Pereira, Calebe Diogo, Ariene Fonseca, Larissa Bomfim, Pedro Cardoso, Anna Santos, Uilla Dittz, Kildare Miranda, Wanderley de Souza, Adriana Gioda, Enrique R. D. Calderon, Luciana Araripe, Rafaela Bruno, Isabela Ramos Follicular atresia is the mechanism by which the oocyte contents are degraded during oogenesis in response to stress conditions, allowing the energetic resources stored in the developing oocytes to be reallocated to optimize female fitness. Autophagy is a conserved intracellular degradation pathwa y where double-membrane vesicles are formed around target organelles leading to their degradation after lysosome fusion. The autophagy-related protein 8 (ATG8) is conjugated to the autophagic membrane and has a key role in the elongation and closure of the autophagosome. Here we identified one singl e isoform of ATG8 in the genome of the insect vector of Chagas DiseaseRhodnius prolixus (RpATG8) and found that it is highly expressed in the ovary during vitellogenesis. Accordingly, autophagosomes were detected in the vitellogenic oocytes, as seen by immunoblotting and electron microscopy. To test if autophagosomes were important for follicular atresia, we silenced RpATG8 and elicited atresia in vitellogenic females by Zymosan-A injections. We found that silenced females were still able to trigger the same levels of follicle atresia, and that their atretic oocytes presented a characteristic morphology, with accumulated brown aggregates. Regardless of the dif...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research