Sperm Motility**This work has been supported by Career Development Award 2 K3-GM-15, 193-06 and by Research Grant GM 06815-06 of the National Institutes of Health. The author also wishes to acknowledge prior support from the Commonwealth Fund in the form of a travel grant.

Nelson, Leonard

doi:10.1016/b978-1-4832-2776-4.50008-3

Cited by 16 publications

References 153 publications

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Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species

1974

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Treatment of immature and mature epididymal spermatoz,oa with SDS and DTT reveals differences in the structural character of their respective tail organelles as a function of their maturity, which are riot apparent in untreated spermatozoa. The response of mature sperm tails of rat, rabbit and other mammals to these reagents indicates that the segmented connecting pieces. the coarse outer fibers, the outer membrane of the mitochondrion and the fibrous sheath of the principal piece, as well as the relationships between these organelles, are stabilized highly by intermolecular -SScrosslinks. The disruption of these structures by SDS alone in caput epididymal spermatozoa, however, implies their stabilization by disulfide bonds during sperm passage through the epididymis. Hence the pattern of flagellar beat seen typically i n mature epididy-ma1 or ejaculated spermatozoa is probably determined by post-spermiation changes in the structural as well as in the metabolic properties of the tail organellcs.In similar studies of a wide variety of sub-mammalian species, the sperm tails fell into two broad classes. The "simple" tail, a plasma membrane enclosing only mitochondria and microtubule doublets (teleosts, frog, chicken and pigeon), disappeared immediately in SDS, though a partial -%Sdependent stability was inducible in the microtubules of telcost sperm tails. In the second class, the coarse fibers, arrayed as a nine-membered ring (octopus, snake, lizard, turtle and sparrow) or otherwise (skate, newt), and the fibrous sheath (snake, lizard) also are stabilized by 4 -S -bonds, as is the undulating membrane of the urodele sperm tail.Since the sperm mitochondria in all sub-mammalian species were totally disrupted hy SDS alone, an extreme -S-% dependent stability of the outer mitochondrial membrane may well be a feature unique to mammalian spermatozoa.

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Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species

1974

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A new model for the structure of the centriolar satellite complex in spermatozoa

Summers

1972

Journal of Morphology

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The ultrastructure of the centriolar satellite complex i n the spermatozoon of the hydroid, Pennaria, is presented. The complex consists of nine spoke-like arms which emanate from the distal centriole and of nine wedgeshaped connectives which extend into the flagellum joining each of the alpha doublets and the flagellar plasmalemma. Based upon these observations a new model for the structure of the centriolar satellite complex is proposed. In addition, similar centriolar satellite complexes are reported in the spermatozoa of two echinoderms, Ctenodiscus crispatus and Thyone briareus, in support of the proposed model. Striated pericentriolar structures suggestive of centriolar satellites were first reported by Galtsoff and Philpott ('60) in the spermatozoon of the oyster, Crassostrea. However, attention was first called to the morphology of these structures by Colwin and Colwin ('61) in their ultrastructural studies of the spermatozoon of the polychaete annelid, Hydroides. More recently, Szollosi ('64) presented a threedimensional reconstruction of the centriole-satellite complex in his extensive investigation of the spermatids of the hydromedusan, Phialidium. He depicted nine spoke-like structures which emanate from the matrix of the distal (filament forming) centriole and which extend radially to the spermatid plasmalemma. The satellites in Phialidium are branched at their distal ends and are composed of periodically striated, electron opaque material. Whether or not these satellites are present i n the spermatozoon of this species is not known, since Szollosi's report did not illustrate the complex in the mature spermatozoon.In more recent investigations, centriolar satellites have been identified in either spermatids or spermatozoa of 19 invertebrate and three vertebrate species (table 1). Despite the numerous reports of its occurrence, little attention has been given to the detailed ultrastructure of this interesting complex. This paper presents ultrastructural observations on the centriolar satellite complex in the spermatozoon of the hydroid, Pennaria and two additional organisms, Ctenodiscus and Thyone, and relates a model derived from these observations to the electron microscopic observations of other investigators. MATERIALS AND METHODSHydranths of Pennaria tiarella bearing mature male gonophores were collected near Flatts' Bridge, Bermuda Islands. Specimens of Ctenodiscus crispatus were obtained i n deep water trawls from the coastal waters of Maine. Male Thyone briareus were provided by the Supply Department of the Marine Biological Laboratory, Woods Hole, Mass.Whole male gonomedusae were removed from the hydranths of Pennaria and testicular lobes were dissected from Ctenodiscus and Thyone. Gonophores and testes were fixed for two hours in 3% glutaraldehyde i n sea water at 4" C. Following fixation, the specimens were washed overnight in cold sea water and then postfixed in 1% OsOl in sea water at 4 " C. Subsequently, they were passed through graded ethanols at 4" C and acetone (or propylene ...

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A light and electron microscopical study of spermatogenesis in Hydra cauliculata

Moore

Dixon

1972

Journal of Morphology

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Morphological changes i n the interstitial cells were studied during their differentiation into spermatozoa. Development of the spermatogonium involves a n increase in nuclear and nucleolar size, and the formation of a dense mass of cytoplasmic ribosomes. The mature spermatozoon has a relatively simple structure. The head consists of a bullet shaped, homogeneous nucleus, which lacks a n acrosome but bears distal membrane specializations. The middle piece is composed of four large spherical mitochondria at the base of nucleus. A single flagellum projects from one of the two centrioles lodged between the mitochondria. The flagellum appears early during development in the primary spermatocyte. During spermiogenesis microtubules associated with the basal body flagellum complex appear to define the axis of chromatin condensation.

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Sperm Motility**This work has been supported by Career Development Award 2 K3-GM-15, 193-06 and by Research Grant GM 06815-06 of the National Institutes of Health. The author also wishes to acknowledge prior support from the Commonwealth Fund in the form of a travel grant.

Cited by 16 publications

References 153 publications

Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species

Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species

A new model for the structure of the centriolar satellite complex in spermatozoa

A light and electron microscopical study of spermatogenesis in Hydra cauliculata

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