SOME OBSERVATIONS ON THE FINE STRUCTURE OF ARMADILLO SPERMATOZOA
| Autor: | F. Nagy, R. H. Edmonds |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Male
Embryology Morphology (linguistics) Uranyl acetate law.invention chemistry.chemical_compound Endocrinology law biology.animal Animals Acrosome Fixative Cell Nucleus Epididymis biology Obstetrics and Gynecology Cell Biology Anatomy Xenarthra biology.organism_classification Spermatozoa Mitochondria Organoids Microscopy Electron Dasypus novemcinctus Reproductive Medicine chemistry Osmium tetroxide Armadillo Electron microscope Lysosomes |
| Zdroj: | Reproduction. 34:551-553 |
| ISSN: | 1741-7899 1470-1626 |
| Popis: | In the present report, we present certain facets of the fine structure of the epididymal spermatozoa of an edentate, the nine-banded armadillo, Dasypus novemcinctus mexicanus. Although numerous investigators have devoted considerable attention to the morphology of spermatozoa using both transmission (Cleland & Rothschild, 1959; Bedford, 1965; Blom & Birch-Andersen, 1965; Nicander & Bane, 1966; Fawcett & Ito, 1965; Phillips, 1970; Pedersen, 1970; Phillips, 1972) and scanning (Koehler, 1970) electron microscopes, the armadillo represents a mammalian species in which the fine structure of the spermatozoa has not been investigated. While numerous features common to most mammalian spermatozoa have been observed in the armadillo, we report here some of the more distinctive features. Sexually mature, male, nine-banded armadillos were examined during April and May. The animals were maintained for brief periods in the laboratory before they were killed with an overdose of Nembutal. Under light Nembutalinduced anaesthesia, the epididymides were removed and immediately im¬ mersed in a phosphate-buffered paraformaldehyde-glutaraldehyde solution (Karnovsky, 1965). The epididymides were divided into initial, middle and terminal segments and minced tissue was then placed in fresh fixative for 2 hr. Tissues were post-fixed in 1 % phosphate-buffered osmium tetroxide for an additional 2 hr, dehydrated in a graded series of ethanols, infiltrated and em¬ bedded in Epon 812 (Finck, 1960). Thin sections for electron microscopy were cut using glass knives and were stained with uranyl acetate and lead citrate to enhance contrast. Sections were examined in an RCA-EMU-3E electron microscope with a modified condenser at accelerating voltages of 50 and 100 kV. The frontal plane of the sperm head is paddle-shaped, whereas the sagittal profile is ensiform and exhibits an acrosome with three distinct regions: an apical portion, a thick main segment and a thin equatorial segment. The main portion of the acrosome is characterized by a marginal thickening which extends to the junction of the main portion and the equatorial segment. The contents of the three acrosomal segments appear to be uniformly electron-dense (PI· L Fig. 1). In keeping with the general morphology of mammalian spermatozoa, the paddle-shaped armadillo sperm head resembles that of several species including bulls, rams, boars, guinea-pigs (Nicander & Bane, 1966), chinchillas (Fawcett & Phillips, 1969) and rabbits (Calvin & Bedford, 1971). The ensiform sagittal |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|