ROLE OF ACID HYDROLASES DURING FOLLICULAR ATRESIA IN A VECTOR OF CHAGAS´ DISEASE.

LEYRIA J; AGUIRRE SA; FRUTTERO LL; CARLINI CR; RUBIOLO ER; CANAVOSO LE

San Juan, Argentina

Jornada; 2º Reunión Conjunta de Sociedades de Biología de la República Argentina, XVIII Jornadas Científicas de la Sociedad de Biología de Córdoba; 2011

Sociedades de Biología de la República Argentina

In insects, unfavourable nutritional conditions induce biochemical and cellular changes in the ovarian tissue such as the early degradation of vitellin (Vt), the main oocyte protein, and the atresia of some follicles. In some species, the changes accomplished during atresia are elicited to promote the recycling of proteins to sustain younger follicles. In this study, we have explored biochemical changes that take place during the process of follicular atresia induced by a nutritional deficit in the hematophagous Dipetalogaster maxima, a vector of Chagas? disease. We have emphasized in the roles of two acid hidrolases, cathepsin D (CD) and acid phosphatase (AP). The study included assays of western-blot, the measurement of enzyme activities, immunofluoresce as well as in vitro assays of Vt proteolysis employing specific inhibitors of CD and AP. Results showed that proteolysis of Vt occurred gradually during the transition from vitellogenesis to follicular atresia. Higher activities of AP and CD were registered at early and late atresia, in comparison to pre-vitellogenesis and vitelogenesis. In vitro assays showed that AP is important in promoting Vt degradation, which in turn was mediated by CD. Altogether, the biochemical changes exhibited during follicular atresia in D. maxima could reflect the ability of the ovarian tissue to face a new vitellogenic cycle if nutritional conditions improve. The results also provide a better understanding of the biology of reproduction of Chagas? disease vectors.