scholarly journals Sperm dimorphism in terms of nuclear shape and microtubule accumulation in Cyrtanthus mackenii

2009 ◽  
Vol 23 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Tomonari Hirano ◽  
Yoichiro Hoshino
Keyword(s):  
Nuclear Shape ◽  
Cyrtanthus Mackenii ◽  
Sperm Dimorphism

ALPHA DECAY AND FISSION OF ALIGNED NUCLEI

1960 ◽  
Vol 38 (2) ◽  
pp. 290-314 ◽  
Author(s):  
N. R. Steenberg ◽  
R. C. Sharma
Keyword(s):  
Angular Distribution ◽  
High Temperature ◽  
Experimental Work ◽  
Low Temperatures ◽  
Alpha Decay ◽  
Alpha Particles ◽  
Nuclear Shape ◽  
Fission Fragments ◽  
Partial Waves ◽  
High Temperature Approximation

The theory of the angular distribution of alpha particles and of fission fragments from nuclei aligned at low temperatures is presented. Very explicit results are obtained in the high temperature approximation. These are directly dependent upon the branching which takes place to the various allowed partial waves. This branching is influenced by the nuclear shape, but it is shown that for this problem the effect of penetrating a spheroidal barrier is not critical. An application is made to the experimental work so far available and the result is reasonably satisfactory.

Ultrastructural evidence of sperm dimorphism in Deladenus sp. (Tylenchomorpha: Sphaerularioidea: Allantonematidae)

Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 397-404 ◽  
Author(s):  
Hajime Kosaka ◽  
Manabu Kusunoki ◽  
Vladimir Yushin
Keyword(s):  
Electron Microscope ◽  
Parasitic Nematode ◽  
Spermatogenic Cells ◽  
Ultrastructural Evidence ◽  
Transmission Electron ◽  
Parallel Fibres ◽  
Sperm Dimorphism ◽  
Whole Life Cycle ◽  
First Time ◽  
Spherical Vesicles

AbstractThe dimorphic spermatozoa of the insect-parasitic nematode Deladenus sp. (Tylenchomorpha: Sphaerularioidea: Allantonematidae) were studied for the first time with a transmission electron microscope (TEM). The immature spermatozoa from the testis of mycetophagous males are 10-12 μm diam. and 4-5 μm long unpolarised cells with a centrally located nucleus without a nuclear envelope. The cytoplasm contains mitochondria and specific components, membranous organelles (MO) and fibrous bodies (FB). The MO are spherical vesicles with an internal system of finger-like invaginations of the membrane; the spindle-shaped FB consist of tightly packed parallel fibres. Spermatozoa from the uteri of infective females of Deladenus sp. are vastly different in size being tiny cells ca 2 μm diam. with a spherical or oval nucleus. Each cell contains several mitochondria and MO. Although each individual of Deladenus sp. contains only monomorphic spermatozoa, sperm dimorphism was revealed after analysis of the whole life cycle. Despite a difference in size the cytological characters of both types of spermatozoa conform to the typical rhabditid pattern. The presence of both MO and FB in sphaerularioidid spermatozoa differentiates the superfamily Sphaerularioidea from Tylenchoidea whose representatives lack MO in the spermatogenic cells.

Effect of a Triaxial Nuclear Shape on Proton Tunneling: The Decay and Structure ofTm145

2007 ◽  
Vol 99 (8) ◽  
Author(s):  
D. Seweryniak ◽  
B. Blank ◽  
M. P. Carpenter ◽  
C. N. Davids ◽  
T. Davinson ◽  
...  
Keyword(s):  
Nuclear Shape ◽  
Proton Tunneling

scholarly journals An RNAi screen for genes that affect nuclear morphology in Caenorhabditis elegans reveals the involvement of unexpected processes

2021 ◽  
Author(s):  
Richa Maheshwari ◽  
Mohammad M Rahman ◽  
Daphna Joseph-Strauss ◽  
Orna Cohen-Fix
Keyword(s):  
Caenorhabditis Elegans ◽  
Nuclear Pore Complex ◽  
Cellular Transformation ◽  
Rnai Screen ◽  
Nuclear Shape ◽  
Nuclear Pore ◽  
Nuclear Morphology ◽  
Anaphase Bridges ◽  
Early Embryos ◽  
Embryonic Viability

Abstract Aberration in nuclear morphology is one of the hallmarks of cellular transformation. However, the processes that, when mis-regulated, result aberrant nuclear morphology are poorly understood. In this study we carried out a systematic, high-throughput RNAi screen for genes that affect nuclear morphology in Caenorhabditis elegans embryos. The screen employed over 1700 RNAi constructs against genes required for embryonic viability. Nuclei of early embryos are typically spherical, and their NPCs are evenly distributed. The screen was performed on early embryos expressing a fluorescently tagged component of the nuclear pore complex (NPC), allowing visualization of nuclear shape as well as the distribution of NPCs around the nuclear envelope. Our screen uncovered 182 genes whose down-regulation resulted in one or more abnormal nuclear phenotypes, including multiple nuclei, micronuclei, abnormal nuclear shape, anaphase bridges and abnormal NPC distribution. Many of these genes fall into common functional groups, including some that were not previously known to affect nuclear morphology, such as genes involved in mitochondrial function, the vacuolar ATPase and the CCT chaperonin complex. The results of this screen add to our growing knowledge of processes that affect nuclear morphology and that may be altered in cancer cells that exhibit abnormal nuclear shape.

scholarly journals Nuclear Morphology Optimized Deep Hybrid Learning (NUMODRIL) For Accurate Diagnosis and Prognosis of Ovarian Cancer

2021 ◽  
Author(s):  
Duhita Sengupta ◽  
Sk Nishan Ali ◽  
Aditya Bhattacharya ◽  
Joy Mustafi ◽  
Asima Mukhopadhyay ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Morphological Changes ◽  
Hybrid Learning ◽  
Nuclear Shape ◽  
Machine Learning Techniques ◽  
Serous Carcinoma ◽  
Altered Expression ◽  
Diagnosis And Prognosis ◽  
Wide Range

Abstract Nuclear morphological features are potent determining factors for clinical diagnostic approaches adopted by pathologists to analyse the malignant potential of cancer cells. Considering the structural alteration of nucleus in cancer cells, various groups have developed machine learning techniques based on variation in nuclear morphometric information like nuclear shape, size, nucleus-cytoplasm ratio and various non-parametric methods like deep learning have also been tested for analysing immunohistochemistry images of tissue samples for diagnosing various cancers. Our aim is to study the morphometric distribution of nuclear lamin proteins as a specific parameter in ovarian cancer tissues. Besides being the principal mechanical component of the nucleus, lamins also present a platform for binding of proteins and chromatin thereby serving a wide range of nuclear functions like maintenance of genome stability, chromatin regulation. Altered expression of lamins in different subtypes of cancer is now evident from data across the world. It has already been elucidated that in ovarian cancer, extent of alteration in nuclear shape and morphology can determine degree of genetic changes and thus can be utilized to predict the outcome of low to high form of serous carcinoma. In this work, we have performed exhaustive imaging of ovarian cancer versus normal tissue and introduced a novel Deep Hybrid Learning approach on the basis of the distribution of lamin proteins. Although developed with ovarian cancer datasets in view, this architecture would be of immense importance in accurate and fast diagnosis and prognosis of all types of cancer associated with lamin induced morphological changes and would perform across small/medium to large datasets with equal efficiency.

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