Involvement of two acid hidrolases in the follicular atresia in Dipetalogaster maxima (Hemiptera: Reduviidae)

LEYRIA, J.; NAZAR, M.; FRUTTERO, L.L.; RUBIOLO, E.R.; CANAVOSO, L.E.

La Falda, Córdoba.

Jornada; XIX Jornadas Científicas de la Sociedad de Biología de Córdoba; 2013

Sociedad de Biología de Córdoba

In insects, unfavorable nutritional conditions induce changes in the ovarian tissue that in turn, promote follicular atresia. In this process, early degradation of vitellin (Vt), the main oocyte protein, and oocyte resorption take place. In the vectors of Chagas´ disease, follicular atresia is poorly understood. The aim of this work was to study the biochemical and molecular events that take place during follicular atresia induced by nutritional deprivation in Dipetalogaster maxima, with special focus on two acid hydrolases, cathepsin D (CD) and acid phosphatase (AP). The study included enzymatic and western blot assays, RT-qPCR and in vitro assays of Vt proteolysis. The results showed that in the ovary, CD is expressed in all reproductive stages, being the active form more expressed during atresia, in correlation with its activity profile. AP was differentially activated throughout the reproductive cycle and most of such activity corresponded to a tyrosine phosphatase. In vitro assays demonstrated that AP was important in promoting Vt degradation, which in turn was mediated by CD. Our findings suggest that early activation of CD and AP during follicular atresia may be important in the homeostasis of ovarian tissue to either, increase female lifespan or maintain younger oocytes until improvement ofnutritional conditions.