VITELLOGENESIS AND FOLLICULAR ATRESIA: THEIR IMPACT IN THE REPRODUCTIVE PHYSIOLOGY OF THE CHAGAS´ DISEASE VECTORS.

LEYRIA, JIMENA

La Falda, Córdoba

Jornada; XXI Jornada Científica Sociedad de Biología de Córdoba; 2017

Sociedad de Biología de Córdoba

In triatomines, adult females need the ingestion of a blood meal to trigger vitellogenesis, allowing the growth of oocytes due to the uptake and storage of yolk proteins precursors (YPP), lipids and other molecules. However, if the blood intake is insufficient to promote the vitellogenic process, the ovarian tissue undergoes remarkable histo-morphological changes and some follicles degenerate to an atretic stage. During this process, oocytes undergo resorption (oosorption) instead of being laid as eggs. From a physiological point of view, an adequate compromise between the factors that regulate vitellogenesis and follicular atresia allows a successful ovogenesis. In this work, we have analyzed the biochemical, cellular and molecular events that characterize vitellogenesis and follicular atresia in vectors of Chagas' disease (Hemiptera: Reduviidae), using the female Dipetalogaster maxima as a model. We determined that the oocytes recruited lipids by different pathways according to the stage of the reproductive cycle. On the other hand, we reported that an aspartic peptidase, cathepsin D (DmCatD), is synthesized by the fat body and the ovary as YPP. In addition, we presented for the first time evidences that supports the function of lipophorin, the main insect lipoprotein, as a carrier for DmCatD. This novel pathway would facilitate the internalization of DmCatD by the oocytes. Altogether, our results allow us to a better understanding of the biology of the reproduction of vectors of Chagas' disease, which in turn is necessary in the search of new tools for insect vector control