Ultrastructure and histopathological alteration in the ovaries of Callosobruchus maculatus (F.) (Coleoptera, Chrysomelidae) induced by the solar radiation

The ultrastructure and histopathological changes in the ovarioles were tested in normal adult females and in those developed from solar energy treated pupae (53 °C for 15 min) of Callosobruchus maculatus. The telotrophic ovarioles of C. maculatus contain germarium region followed by vitellarium region which constitutes the vitellarium.

The germarium houses trophocytes and the vitellarium consists of ovarian follicles.

At the germarium region of the ovariole, the trophocyte or nurse cell nucleus contains uniformly spaced clumps of heterochromatin. The cytoplasm contains numerous free ribosomes and mitochondria.

At the vitellarium region, follicular epithelial cells form a layer around the oocyte, each cell contains a large oval nucleus with abundant heterochromatin, and the cytoplasm contains mitochondria, free ribosomes and dark spherical globules. Also the vitellarium includes the previtellogenic oocyte which is the most anterior one and two last vitellogenic oocytes at the posterior end as the yolk was deposited.

Oocyte microvilli are interdigitated with those of the follicle cells. The ooplasm consists primarily of electron-dense yolk bodies and lipid droplets.

These phases could be identified in the ovarioles of normal females and to a less extent in those of females developed from the treated pupae. In the ovarian follicles of the treated generation, degeneration of the cell components of trophocytes, follicular epithelium and oocytes were the most obvious signs of damage. Also, lacking of yolk bodies and vacuolation in the border of the ooplasm were observed.

The damage was more pronounced in the ovarioles of (F.) progeny of the treated generation.