Biomaterial Database

Toxocara canis: ultrastructural aspects of larval moulting in the maturing eggs. 1995

M Brunaská, and P Dubinský, and K Reiterová

Parasitological Institute, Slovak Academy of Sciences, Kosice.

The morphology of the surface of Toxocara canis larvae, developing in the eggs to reach infectivity, has been studied for the first time at an electron microscopical level. In most 11-day and some 15-day eggs, the larvae are surrounded by two shed cuticles. The outer first shed cuticle is composed of two layers. the inner second shed cuticle is much thicker than the outer one. The presence of both shed cuticles indicates that the larva has undergone two developmental stages in the maturing egg. The larvae in most 15-day eggs are surrounded by one shed cuticle composed of outer electron-dense and inner layers. This cuticular sheath is identical with the described inner second shed cuticle, except for its apparently reduced thickness. The infective larvae inside the 30-day eggs are enveloped by one cuticular sheath, derived from the second moulted cuticle, and consisting only of a single layer. The findings are discussed with respect to data concerning the moulting process in other nematode species.

UI	MeSH Term	Description	Entries
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D008675	Metamorphosis, Biological	Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.	Biological Metamorphosis,Biological Metamorphoses,Metamorphoses, Biological
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010063	Ovum	A mature haploid female germ cell extruded from the OVARY at OVULATION.	Egg,Egg, Unfertilized,Ova,Eggs, Unfertilized,Unfertilized Egg,Unfertilized Eggs
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015801	Helminth Proteins	Proteins found in any species of helminth.	Helminth Protein,Protein, Helminth,Proteins, Helminth
D017166	Toxocara canis	A species of parasitic nematode found in the intestine of dogs. Lesions in the brain, liver, eye, kidney, and lung are caused by migrating larvae. In humans, these larvae do not follow normal patterns and may produce visceral larva migrans (LARVA MIGRANS, VISCERAL).	Toxocara cani,canis, Toxocara