CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
THE PLANT UREASE ?JACK BEAN UREASE? ALTERS OOGENESIS IN THE CHAGAS DISEASE VECTOR Rhodnius prolixus (HEMIPTERA: REDUVIIDAE)
Autor/es:
FRUTTERO LL; CANAVOSO LE; MOYETTA NR
Reunión:
Otro; IV REUNIÓN CONJUNTA DE SOCIEDADES DE BIOLOGÍA DE LA REPÚBLICA ARGENTINA; 2020
Institución organizadora:
Sociedades de Biología de la República Argentina
Resumen:
Ureases are enzymes that catalyze the hydrolysis of urea in carbon dioxide and ammonia. In the last decades, it was postulated that plant ureases are also defense proteins against phytophagous insect species, thus presenting biotechnological potential. Previous reports of our group and collaborators demonstrated that the injection of ?Jack Bean Urease? (JBU), the main urease isoform of the leguminous Canavalia ensiformis in the hemocele of triatomine insects elicited different toxic effects, including the activation of the immune response. Even though the insecticidal effect of JBU was described more than fifteen years ago, several aspects of its mechanism of action and target organs are not completely understood. In particular, the effects of this urease on the reproductive system of females and the consequences of sub-lethal doses were not studied yet. In this work, we employed the Chagas disease vector Rhodnius prolixus as a model in order to study the effects of JBU on the survival, ovarian development and oviposition of females. Firstly, it was standardized an injection protocol to obtain control insects without affecting their survival and oviposition capacity. For that purpose, control individuals without injection vs. control individuals injected with vehicle were compared after receiving a blood meal. Thereafter, the assays were conducted comparing control insects injected with phosphate buffer vs. problem insects injected with different doses of JBU in phosphate buffer. The results showed for the first time that a sub-lethal dose of JBU alters different reproductive parameters of R. prolixus females. All tested doses (0.01, 0.025, and 0.05 μg of JBU/mg of body weight) significantly diminished the number of eggs and the highest tested dose of 0.05 μg/mg delayed the beginning of oviposition and hatching. Nevertheless, only the dose of 0.01 μg of JBU/mg did not result in insect mortality. In the case of this sub-lethal dose, the diminution of the number of eggs resulted in an extended longevity of the insects. On the morphological level, it was shown that the ovaries of JBU-treated insects were less developed and presented atretic follicles. Future studies will be performed to unravel the cell death mechanism(s) that participate in JBU-induced follicle degradation. Taking into account the relevance of reproduction and oviposition in the population dynamics of pest insects and disease vectors, our findings reveal a new aspect of the entomotoxic effect of JBU that reinforces its importance as a promising tool to control harmful species.