Results 161 to 170 of about 22,975 (207)

Microtubules in the spermatid of the rabbit

Zeitschrift f�r Zellforschung und Mikroskopische Anatomie, 1969
In the cytology of the developing rabbit spermatid two systems of microtubules are conspicuous features. One corresponding to the manchette of light microscopy is in correlation with changes in the nuclear membrane giving rise to the posterior nuclear space.
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Transformation of ram spermatid chromatin

Experimental Cell Research, 1978
Abstract In order to investigate the sequence of changes in nuclear basic proteins throughout ram spermiogenesis, we have used different techniques to obtain populations of spermatid nuclei in specific stages of maturation. Sedimentation of testis cells at 1 gravity followed by treatment with Triton X-100 resulted in one population of round spermatid
M, Loir, M, Lanneau
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Nuclear reorganization in ram spermatids

Journal of Ultrastructure Research, 1979
Nuclear changes as a function of ram spermatid differentiation have been studied using electron microscopy, cytochemistry, and treatment of isolated nuclei with chemical and mechanical agents. In round nuclei, chromatin consists of intertwined knobby fibers about 210 and 120 A in diameter.
M, Loir, J L, Courtens
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Hormonal regulation of spermatid binding

Journal of Cell Science, 1991
ABSTRACT A Sertoli-spermatid coculture model is described in which a large percentage (>76%) of round spermatids remain viable for 48 h and bind to Sertoli cells. The effects of follicle-stimulating hormone (FSH) and testosterone on spermatid binding (expressed as the spermatid density; SD- the number of spermatids per unit area ...
D F, Cameron, K E, Muffly
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Nuclear shaping in marsupial spermatids

Journal of Ultrastructure Research, 1972
Nuclear shaping was investigated in two species of American opossum, Didelphus virginiana and Marmosa mitus. The mature spermatozoan head achieves its “U” shaped form by the progressive flattening of the posterior margin of the nucleus and the development of a protrusion on one side of the nucleus.
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Microtubules in the spermatids of stick insects

Journal of Ultrastructure and Molecular Structure Research, 1988
Spermatids from two phasmid species were seen to possess an unusually large amount of microtubules along the nucleus and tail. Some of the microtubules have a loosely fitting sleeve for half a micron or more. During late stages in spermiogenesis the microtubules aggregate and form one or several "microtubular crystals" consisting of electron-lucid ...
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Intranuclear whorls in the hamster spermatid

Journal of Ultrastructure Research, 1969
In the 2-week-old hamster, intranuclear whorls were observed in cells located among the spermatids. The whorls, measuring up to 2.5 μ in diameter, were composed of sheets of microtubules. The distance between the individual sheets was 150 A, the tubular lumen was 80 A, and the tubular wall measured 120 A. It is assumed that the presence of intranuclear
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Centrioles in the Spermatids of Insects1

Annals of the Entomological Society of America, 1968
The University of Texas at Austin There have been many statements published regarding the number of centrioles in the spermatids of insects. Some earlier workers reported the occurrence of 2 centrioles in several groups of insects, although only one was seen in the spermatids of some species (summarized in Wilson 1928).
Osmond P. Breland, Kenneth R. Barker, Charles D. Eddleman, John J. Biesele   +3 more
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Spermatids and Spermiogenesis

1987
The two maturation divisions of each spermatocyte result in four haploid cells, spermatids. These differentiate into spermatozoa, a process called spermiogenesis which ends when the spermatozoa are released from the seminiferous epithelium. After the haploid round spermatids are formed, their nuclear and cytoplasmic components undergo a complex series ...
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Spermatid conception

Human Reproduction, 1998
Silber, Sherman, Verheyen, Greta, Van Steirteghem, Andre   +2 more
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