Biomaterial Database

Morphology of the spermatid and spermatozoon of Amblyomma hebraeum Koch (Acarina; Ixodidae). 1978

J Wüest, and A E Said, and Z Swiderski, and A Aeschlimann

Spermatids and spermatozoa of Amblyomma hebraeum were examined by scanning and transmission electron microscopy as well as by freeze-etch and freeze-fracture techniques. The external surface of the spermatid is smooth except for a rim of two parallel grooves near the anterior apex. This rim probably marks the level at which a cap detaches, permitting extrusion of the inner cord during spermatozoon maturation. Both ends of the spermatid are closed, the anterior part being slightly thicker than the posterior. The spermatozoon is clavate anteriorly and tail-like posteriorly. The tip of the anterior part is a hemispherical structures carrying numerous bulbous expansions. Apart from the hemispherical structure, the entire spermatozoon surface is covered with parallel longitudinal cellular processes. Waves of constrictions on the tail-like part of the spermatozoon and undulations of the cellular processes are considered to be involved in sperm motility.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008925	Mites	Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.	Acarus,Mite
D005613	Freeze Etching	A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.	Etching, Freeze
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
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
D013081	Sperm Motility	Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.	Motilities, Sperm,Motility, Sperm,Sperm Motilities
D013087	Spermatids	Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.	Spermatoblasts,Spermatid,Spermatoblast
D013094	Spermatozoa	Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.	Sperm,Spermatozoon,X-Bearing Sperm,X-Chromosome-Bearing Sperm,Y-Bearing Sperm,Y-Chromosome-Bearing Sperm,Sperm, X-Bearing,Sperm, X-Chromosome-Bearing,Sperm, Y-Bearing,Sperm, Y-Chromosome-Bearing,Sperms, X-Bearing,Sperms, X-Chromosome-Bearing,Sperms, Y-Bearing,Sperms, Y-Chromosome-Bearing,X Bearing Sperm,X Chromosome Bearing Sperm,X-Bearing Sperms,X-Chromosome-Bearing Sperms,Y Bearing Sperm,Y Chromosome Bearing Sperm,Y-Bearing Sperms,Y-Chromosome-Bearing Sperms