Ultrastructural Studies of the Nuclear Envelope in Human Sperm

1982 ◽  
Vol 9 (3) ◽  
pp. 195-201 ◽  
Author(s):  
K. Jamil
Keyword(s):  
Nuclear Envelope ◽  
Human Sperm ◽  
Ultrastructural Studies

Ultrastructural studies in the Rhodophyta. I. Development of mitotic spindle poles in Apoglossum ruscifolium, Kylin

1982 ◽  
Vol 58 (1) ◽  
pp. 345-362
Author(s):  
A.J. Dave ◽  
M.B. Godward
Keyword(s):  
Nuclear Envelope ◽  
Red Algae ◽  
Mitotic Spindle ◽  
Natural Habitat ◽  
Subsequent Development ◽  
Spindle Pole ◽  
Nuclear Pore ◽  
Evolutionary Stage ◽  
Ultrastructural Studies ◽  
Polar Ring

The ultrastructure of somatic mitosis in the germlings of Apoglossum ruscifolium, Kylin, fixed from its natural habitat, was examined to investigate spindle-pole development and the role of the ‘polar ring’. It was found that the polar ring originates from a special nuclear pore raised above a small projection of the nuclear envelope. The initiation of mitotic polarity takes the form of changes in the nuclear envelope. These are: close crowding of pores, heavy deposition of electron-opaque material and attachment of microtubules. No such phenomena are to be observed in the equatorial regions of the nuclear envelope, which persists throughout mitosis. The next stage is the development of ‘clear zones’, which become filled with microtubules excluding all other structures, notably ribosomes, at both poles. At pre-metaphase, microtubules begin to be extended from the clear zones through polar fenestrae in the nuclear envelope into the nucleus itself. With subsequent development of the intranuclear spindle, the microtubules in the clear zones show signs of degeneration. At metaphase, the polar regions of the nuclear envelope begin to return to their normal condition. After metaphase, the polar rings degenerate. Thus it is primarily the nuclear envelope, via its polar modifications, which begins the organization of the mitotic spindle. The capabilities of nuclear pores are summarized. In the Discussion, the polar rings are compared with procentrioles; since they appear to have a passive role in spindle-pole organization, it is suggested that they may represent an evolutionary stage prior to the procentriole. The origin of the centriole ultimately from a nuclear pore is presented as an hypothesis. It is concluded to be unlikely that the polar ring is a degenerate centriole, and therefore it is proposed that the red algae never had centrioles in the course of their evolution. Thus the view of the non-flagellate ancestry of the red algae is supported.

Untersuchungen über die Ultrastruktur von Saprolegnia monoica / Ultrastructural Studies of Saprolegnia monoica

1971 ◽  
Vol 26 (8) ◽  
pp. 843-849 ◽  
Author(s):  
Herbert Hagedorn ◽  
Heinz Weinert
Keyword(s):  
Cell Wall ◽  
Nuclear Envelope ◽  
Transitional Region ◽  
Multivesicular Bodies ◽  
Ultrastructural Studies

In the tip region of a young hyphae vesicles with a diameter of 0.18 μ and vacuoles form the “Spitzenkörper”. This special differentiation is missed in old stages of hyphae. The vesicles enlarge the CM. The lomasomes in the transitional region serve for the synthesis of cell wall substances. Nuclearenvelope, ER, dictyosomes, vesicles and CM are accounted as a connecting system. The dictyogenesis from vesicles of the ER or the nuclear envelope is described. The mitochondria which occur different in the regions of the hyphae form potlike stages which contain lipoid droplets in their inside. Furthermore there occur isolated lipoid droplets which are in exchange with “polygonale bodies”, which are considered as glycoproteids. Multivesicular bodies, ER-vesicles and vacuoles are described too.

scholarly journals Genetic and ultrastructural studies in dilated cardiomyopathy patients: a large deletion in the lamin A/C gene is associated with cardiomyocyte nuclear envelope disruption

2010 ◽  
Vol 105 (3) ◽  
pp. 365-377 ◽  
Author(s):  
Pallavi Gupta ◽  
Zofia T. Bilinska ◽  
Nicolas Sylvius ◽  
Emilie Boudreau ◽  
John P. Veinot ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Dilated Cardiomyopathy ◽  
Large Deletion ◽  
Lamin A ◽  
Ultrastructural Studies

scholarly journals Homozygous mutation in SLO3 leads to severe asthenoteratozoospermia due to acrosome hypoplasia and mitochondrial sheath malformations

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Mingrong Lv ◽  
Chunyu Liu ◽  
Chunjie Ma ◽  
Hui Yu ◽  
Zhongmei Shao ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Missense Variant ◽  
Human Sperm ◽  
Human Case ◽  
Chinese Patient ◽  
Affected Individual ◽  
Homozygous Mutation ◽  
Sequencing Analysis ◽  
Bioinformatic Tools ◽  
Ultrastructural Studies

Abstract Background Potassium channels are important for the structure and function of the spermatozoa. As a potassium transporter, the mSlo3 is essential for male fertility as Slo3 knockout male mice were infertile with the series of functional defects in sperm cells. However, no pathogenic variant has been detected in human SLO3 to date. Here we reported a human case with homozygous SLO3 mutation. The function of SLO3 in human sperm and the corresponding assisted reproductive strategy are also investigated. Methods We performed whole-exome sequencing analysis from a large cohort of 105 patients with asthenoteratozoospermia. The effects of the variant were investigated by quantitative RT-PCR, western blotting, and immunofluorescence assays using the patient spermatozoa. Sperm morphological and ultrastructural studies were conducted using haematoxylin and eosin staining, scanning and transmission electron microscopy. Results We identified a homozygous missense variant (c.1237A > T: p.Ile413Phe) in the sperm-specific SLO3 in one Chinese patient with male infertility. This SLO3 variant was rare in human control populations and predicted to be deleterious by multiple bioinformatic tools. Sperm from the individual harbouring the homozygous SLO3 variant exhibited severe morphological abnormalities, such as acrosome hypoplasia, disruption of the mitochondrial sheath, coiled tails, and motility defects. The levels of SLO3 mRNA and protein in spermatozoa from the affected individual were reduced. Furthermore, the acrosome reaction, mitochondrial membrane potential, and membrane potential during capacitation were also afflicted. The levels of acrosome marker glycoproteins and PLCζ1 as well as the mitochondrial sheath protein HSP60 and SLO3 auxiliary subunit LRRC52, were significantly reduced in the spermatozoa from the affected individual. The affected man was sterile due to acrosome and mitochondrial dysfunction; however, intra-cytoplasmic sperm injection successfully rescued this infertile condition. Conclusions SLO3 deficiency seriously impact acrosome formation, mitochondrial sheath assembly, and the function of K+ channels. Our findings provided clinical implications for the genetic and reproductive counselling of affected families.

Ultrastructure of Cercarial Tails

1974 ◽  
Vol 32 ◽  
pp. 180-181
Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Suitable Host ◽  
Ultrastructural Studies ◽  
Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

The Ultrastructure of the Nuclear Events of Binary Fission in Paramecium bursaria and the Effects of Colchicine on Cell Division

1974 ◽  
Vol 32 ◽  
pp. 276-277
Author(s):  
L. M. Lewis
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Condensed Chromatin ◽  
Binary Fission ◽  
Paramecium Bursaria ◽  
Nuclear Events ◽  
Division Axis

The effects of colchicine on extranuclear microtubules associated with the macronucleus of Paramecium bursaria were studied to determine the possible role that these microtubules play in controlling the shape of the macronucleus. In the course of this study, the ultrastructure of the nuclear events of binary fission in control cells was also studied.During interphase in control cells, the micronucleus contains randomly distributed clumps of condensed chromatin and microtubular fragments. Throughout mitosis the nuclear envelope remains intact. During micronuclear prophase, cup-shaped microfilamentous structures appear that are filled with condensing chromatin. Microtubules are also present and are parallel to the division axis.

Ultra-Rapid Freezing of Isolated Skeletal Muscle Fibers

1977 ◽  
Vol 35 ◽  
pp. 576-577
Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Granular Material ◽  
Nuclear Envelope ◽  
Intracellular Calcium ◽  
Ruthenium Red ◽  
Threshold Concentration ◽  
Rapid Freezing ◽  
Frog Skeletal Muscle ◽  
Electrical Isolation

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.

Scanning and Transmission Electron Microscopy of Endomentrium in Women Wearing TCu-380-A IUD 's

1977 ◽  
Vol 35 ◽  
pp. 666-667
Author(s):  
A. Gonzalez Angulo ◽  
R. Berlioz ◽  
R. Aznar
Keyword(s):  
Copper Wire ◽  
Uterine Cavity ◽  
Morphological Evidence ◽  
Secretory Phase ◽  
Ultrastructural Studies ◽  
Proliferative Phase ◽  
Contraceptive Devices ◽  
Transmission Electron ◽  
Intrauterine Contraceptive ◽  
Myelin Figure

Recent ultrastructural studies on endometrial tissues from women wearing copper, wire intrauterine devices have disclosed morphological evidence of impaired glycogen degradation and secretion resulting in interference with the viability of blastocysts. Reduced microapocrine secretion observed with the scanning electron microscope supports this (1). In addition, organelle modifications have been observed in the epithelial cells of these women. The changes are seen in biopsies taken in the proliferative phase of the cycle and consist of mitochondrial vacuolation and myelin figure formation. These modifications disappear in the secretory phase and therefore have been regarded as reversible (2).The aim of the present studies was to investigate surface epithelial changes as well as organelle modifications in relation to the site of contact with an IUD that releases greater amounts of copper. Endometrial tissue was obtained from the uterine cavity of four young women wearing TCu-380-A intrauterine contraceptive devices for 4-6 weeks.

The Cellular Origin in Atheromatous Lesion

1970 ◽  
Vol 28 ◽  
pp. 202-203
Author(s):  
T. M. Murad ◽  
H. A. I. Newman ◽  
K. F. Kern
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Rabbit Aorta ◽  
Mixed Population ◽  
The Other ◽  
Cellular Origin ◽  
Ultrastructural Studies ◽  
Atherosclerotic Lesions ◽  
Show Evidence ◽  
Early Lesion

The origin of lipid containing cells in atheromatous lesion has been disputed. Geer in his study on atheromatous lesions of rabbit aorta, suggested that the early lesion is composed mainly of lipid-laden macrophages and the later lesion has a mixed population of macrophages and smooth muscle cells. Parker on the other hand, was able to show evidence that the rabbit lesion is primarily composed of lipid-laden cells of smooth muscle origin. The above studies and many others were done on an intact lesion without any attempt of cellular isolation previous to their ultrastructural studies. Cell isolation procedures have been established for atherosclerotic lesions through collagenase and elastase digestion Therefore this procedure can be utilized to identify the cells involved in rabbit atheroma.

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