Changes of nutritional resources in ovarian tissue of Dipetalogaster maxima during the reproductive cycle

LEYRIA, J.; FRUTTERO, L.L.; AGUIRRE, S.A.; 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 hematophagous insects, each gonadotrophic cycle is associated with the intake of a blood meal, which must be appropriated in quantity and quality of nutrients to promote vitellogenesis. Under unfavorable nutritional conditions, changes in ovarian tissue promote follicular atresia and the redistribution of stored nutrients. In this study, we have analyzed the changes of ovarian resources in Dipetalogaster maxima at pre-vitellogenesis, vitellogenesis and fasting-induced early and late atresia (post-vitellogenesis). The amounts of ovarian lipids, proteins and glycogen increased significantly from pre-vitellogenesis to vitellogenesis and then, diminished during atresia. Specific lipid staining of ovarian tissue sections evidenced remarkable changes in the shape, size and distribution of lipid droplets throughout the reproductive cycle. Cellular approaches demonstrated that lipid delivery to oocytes occurred at all reproductive stages, privileging the non-endocytic pathway of lipophorin, the main insect lipoprotein, during the degenerative stage. The results indicated that in females, nutritional deprivation during post-vitellogenesis is relevant in the progression of follicular atresia to either, facilitate insect lifespan or sustain the energetic demand of another gonotrophic cycle.