Morphological and histochemical studies on oogenesis in Callosobruchus analis Fabr. (Bruchidae-Coleoptera).

Abstract

AbstractThe ovary in Callosobruchus analis consists of telotrophic ovarioles with the so called nurse cells confined to one chamber at the anterior end of the ovariole. There are three types of lipids in the ovary: (1) L1 bodies that are present in the early oocytes, in the posterior prefollicular tissue and in the follicular epithelium and contain unsaturated phospholipids; (2) L2 bodies that have a complete or incomplete sheath of phospholipids and a triglyceride core; (3) L3 bodies that are formed of highly saturated triglycerides. Lipids are absent from the trophic tissue. In a mature oocyte the L1 and L2 bodies are cortical in distribution while the L3 bodies are centrally located.The mitochondria contain lipoproteins with RNA. The yolk spheres are acid mucopolysaccharides and protein in nature. The precursors of the yolk spheres appear first in the cortical coplasm and are absent from the follicular epithelium or the trophic tissue. The nucleolus of the oocyte shows evidence of extrusions that are believed to pass into the ooplasm.There are no nutritive cords connecting the trophic tissue to the oocytes; nor is there any evidence of any histochemically demonstrable nutritive material being contributed to the oocyte by the trophic tissue. The circumstantial evidence points towards a contribution of the raw materials to the oocyte by the haemolymph either through or in between the follicular epithelium in some soluble form or as submicroscopic particles.