Accumulation and utilization of lipids during the development of Hymenolepis diminuta cysticercoids

Abstract

The accumulation of neutral lipids in the cells predetermined to evolve into the cyst cavity lining in Hymenolepis diminuta cysticercoids is presented. The differentiation of these cells from the mesenchyma cells and the accompanying synthesis of lipids began in very young, blastula-shaped larvae. Both the number of the cells and the amount of their lipids increased gradually during further development of the parasites. In the pre-encystment stage of the cysticercoids the cells concentrated around the cavity of the prospective cyst. Following encystment, the scolex and the inverted neck became surrounded by a compact mass of the cells, which started using the stored lipids as a source of energy indispensable for the formation of the cyst tissues and of the definitive multilayer lining of the cyst cavity. No neutral lipids were detected in the mature 23-day-old cysticercoids as well as in the experimentally excysted scoleces. Beside a low level of uniformly distributed phospholipids apparently associated with cell membranes, no local accumulations of these substances were observed at any step of the development of the larvae. The utilization of neutral lipids proves both the presence of a lipase-type enzyme(s) and an operative β-oxidation pathway in the cells of the cysticercoids, the latter feature being highly indicative of oxidative metabolism of these larvae.

Ultrastructural and cytochemical studies on vitellogenesis in the trypanorhynch cestode Parachristianella trygonis Dollfus, 1946 (Eutetrarhynchidae)

“…Our studies on the ultrastructure of coracidia of Bothriocephalus clavibothrium (see provide strong arguments for their function as important energy reserves. Also the recent study of Moczoñ (2006) on accumulation and utilization of lipids during the development of Hymenolepis diminuta cysticercoids confirms their important role in cestode morphogenesis. In addition, according to his data, "the utilization of neutral lipids proves both the presence of a lipase-type enzyme(s) and an operative β-oxidation pathway in the cells of the cysticercoids, the latter feature being highly indicative of oxidative metabolism of these larvae" (Moczoñ 2006, p. 152).…”

Fine structural observations on oocyte development, oogenesis and fertilization process of Cotugnia polycantha Diamar, 1893 (Cestoda:Davaineidae) infecting doves (Streptopelia senegalensis)

“…In Killigrewia delafondi (Taeleb and Abdel-Moaty, 2011), lipids represent the most abundant cell inclusion and appear at an earlier stage of oogenesis and vitellogenesis (Świderski and Mokhtar, 1974;korneva, 2001;Świderski et al, 2011). Furthermore, the histochemical study of Moczoń (2006) on the accumulation and utilization of lipids during the development of the cysticercoid metacestode of the cyclophyllidean Hymenolepis diminuta confirmed their important role in cestode morphogenesis. On the other hand, Poddubnaya et al (2005b) reported that the mature oocytes within the lumen of the follicular oviducts are full of cortical granules which are adjacent to the oocyte plasma membrane as clusters.…”

Ultrastructure and cytochemistry of vitellogenesis and the vitellocytes of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (L., 1758) (Gadiformes, Merlucciidae)

“…Our studies on the ultrastructure of the coracidial larva of Bothriocephalus clavibothrium (see provide strong arguments for their functioning as important energy reserves. Furthermore, the histochemical study of Moczoń (2006), on the accumulation and utilisation of lipids during the development of the cysticercoid metacestode of the cyclophyllidean Hy- …”