Marinesco bodies are related to nuclear enlargement in pigment cells of sabstantia nigra

2017 ◽  
Vol 381 ◽  
pp. 281
Author(s):  
R. Amano ◽  
T. Shuta ◽  
M. Yamane ◽  
M. Kitagawa ◽  
K. Hirokawa ◽  
...  
Keyword(s):  
Pigment Cells ◽  
Marinesco Bodies ◽  
Nuclear Enlargement

Nonlinearity of Nuclear Enlargement in Hepatocytes Induced by the Carcinogen N'-Nitrosomorpholine in Ovo

1999 ◽  
Vol 23 (6) ◽  
pp. 485-495 ◽  
Author(s):  
Christiane Wiemann ◽  
Harald Enzmann ◽  
Eckehard Loser ◽  
Gerhard Schluter
Keyword(s):  
In Ovo ◽  
Nuclear Enlargement

scholarly journals The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review

2021 ◽  
Vol 22 (3) ◽  
pp. 1210
Author(s):  
Krzysztof Formicki ◽  
Agata Korzelecka-Orkisz ◽  
Adam Tański
Keyword(s):  
Magnetic Fields ◽  
Developmental Stages ◽  
Negative Influence ◽  
Pigment Cells ◽  
Egg Activation ◽  
Industrial Equipment ◽  
Positive Effects ◽  
Early Developmental Stages ◽  
Species Specific ◽  
Early Developmental

The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.

scholarly journals Nerve-associated Schwann cell precursors contribute extracutaneous melanocytes to the heart, inner ear, supraorbital locations and brain meninges

2021 ◽  
Author(s):  
Marketa Kaucka ◽  
Bara Szarowska ◽  
Michaela Kavkova ◽  
Maria Eleni Kastriti ◽  
Polina Kameneva ◽  
...  
Keyword(s):  
Schwann Cell ◽  
Inner Ear ◽  
Gene Knockout ◽  
Hair Follicles ◽  
Lineage Tracing ◽  
Pigment Cells ◽  
Hearing Function ◽  
Embryonic Origin ◽  
Schwann Cell Precursors ◽  
Evolutionary Aspects

AbstractMelanocytes are pigmented cells residing mostly in the skin and hair follicles of vertebrates, where they contribute to colouration and protection against UV-B radiation. However, the spectrum of their functions reaches far beyond that. For instance, these pigment-producing cells are found inside the inner ear, where they contribute to the hearing function, and in the heart, where they are involved in the electrical conductivity and support the stiffness of cardiac valves. The embryonic origin of such extracutaneous melanocytes is not clear. We took advantage of lineage-tracing experiments combined with 3D visualizations and gene knockout strategies to address this long-standing question. We revealed that Schwann cell precursors are recruited from the local innervation during embryonic development and give rise to extracutaneous melanocytes in the heart, brain meninges, inner ear, and other locations. In embryos with a knockout of the EdnrB receptor, a condition imitating Waardenburg syndrome, we observed only nerve-associated melanoblasts, which failed to detach from the nerves and to enter the inner ear. Finally, we looked into the evolutionary aspects of extracutaneous melanocytes and found that pigment cells are associated mainly with nerves and blood vessels in amphibians and fish. This new knowledge of the nerve-dependent origin of extracutaneous pigment cells might be directly relevant to the formation of extracutaneous melanoma in humans.

Computerised Image Analysis of Nuclear Enlargement Assay in HeLa Cells

1991 ◽  
Vol 19 (1) ◽  
pp. 41-47
Author(s):  
Renato Rizzi ◽  
Francesco Re ◽  
Enzo Chiesara
Keyword(s):  
Image Analysis ◽  
Hela Cells ◽  
Automatic Analysis ◽  
Nuclear Size ◽  
Computerised Image Analysis ◽  
Nuclear Enlargement

It has been observed that cells often respond to carcinogens by nuclear enlargement. For this reason, new morphometric approaches have been developed to evaluate cell modifications in pre-carcinogenesis assays. Morphometric computerised automatic analysis, with original software, was performed on HeLa cells treated with various compounds (hydroxyurea, dimethylnitrosamine, N-methyl- N’-nitro-nitrosoguanidine and cyclophosphamide) to evaluate nuclear size changes.

scholarly journals Strain difference in transgene-induced tumorigenesis and suppressive effect of ionizing radiation

2020 ◽  
Vol 62 (1) ◽  
pp. 12-24
Author(s):  
Bibek Dutta ◽  
Taichi Asami ◽  
Tohru Imatomi ◽  
Kento Igarashi ◽  
Kento Nagata ◽  
...  
Keyword(s):  
Genetic Background ◽  
Malignant Tumors ◽  
Pigment Cell ◽  
Strain Difference ◽  
Inbred Strains ◽  
Suppressive Effect ◽  
Model System ◽  
Pigment Cells ◽  
Transgenic Expression ◽  
Genome Information

Abstract Transgenic expression in medaka of the Xiphophorus oncogene xmrk, under a pigment cell specific mitf promoter, induces hyperpigmentation and pigment cell tumors. In this study, we crossed the Hd-rR and HNI inbred strains because complete genome information is readily available for molecular and genetic analysis. We prepared an Hd-rR (p53+/−, p53−/−) and Hd-rR HNI hybrid (p53+/−) fish-based xmrk model system to study the progression of pigment cells from hyperpigmentation to malignant tumors on different genetic backgrounds. In all strains examined, most of the initial hyperpigmentation occurred in the posterior region. On the Hd-rR background, mitf:xmrk-induced tumorigenesis was less frequent in p53+/− fish than in p53−/− fish. The incidence of hyperpigmentation was more frequent in Hd-rR/HNI hybrids than in Hd-rR homozygotes; however, the frequency of malignant tumors was low, which suggested the presence of a tumor suppressor in HNI genetic background fish. The effects on tumorigenesis in xmrk-transgenic immature medaka of a single 1.3 Gy irradiation was assessed by quantifying tumor progression over 4 consecutive months. The results demonstrate that irradiation has a different level of suppressive effect on the frequency of hyperpigmentation in purebred Hd-rR compared with hybrids.

Introduction: Biology of pigment cells in fish

2002 ◽  
Vol 58 (6) ◽  
pp. 433-434 ◽  
Author(s):  
Masazumi Sugimoto ◽  
Noriko Oshima
Keyword(s):  
Pigment Cells

scholarly journals INHERITED RETINAL DYSTROPHY IN THE RAT

1962 ◽  
Vol 14 (1) ◽  
pp. 73-109 ◽  
Author(s):  
John E. Dowling ◽  
Richard L. Sidman
Keyword(s):  
Pigment Epithelium ◽  
Light And Electron Microscopy ◽  
Retinal Dystrophy ◽  
Photoreceptor Cells ◽  
Pigment Cells ◽  
Membrane Thickness ◽  
Outer Segments ◽  
Progressive Loss ◽  
Retinal Rods ◽  
Microscopy Data

Retinal dystrophies, known in man, dog, mouse, and rat, involve progressive loss of photoreceptor cells with onset during or soon after the developmental period. Functional (electroretinogram), chemical (rhodopsin analyses) and morphological (light and electron microscopy) data obtained in the rat indicated two main processes: (a) overproduction of rhodopsin and an associated abnormal lamellar tissue component, (b) progressive loss of photoreceptor cells. The first abnormality recognized was the appearance of swirling sheets or bundles of extracellular lamellae between normally developing retinal rods and pigment epithelium; membrane thickness and spacing resembled that in normal outer segments. Rhodopsin content reached twice normal values, was present in both rods and extracellular lamellae, and was qualitatively normal, judged by absorption maximum and products of bleaching. Photoreceptors attained virtually adult form and ERG function. Then rod inner segments and nuclei began degenerating; the ERG lost sensitivity and showed selective depression of the a-wave at high luminances. Outer segments and lamellae gradually degenerated and rhodopsin content decreased. No phagocytosis was seen, though pigment cells partially dedifferentiated and many migrated through the outer segment-debris zone toward the retina. Eventually photoreceptor cells and the b-wave of the ERG entirely disappeared. Rats kept in darkness retained electrical activity, rhodopsin content, rod structure, and extracellular lamellae longer than litter mates in light.

Developmental potential of neural crest-derived cells migrating from segments of developing quail bowel back-grafted into younger chick host embryos

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 411-423 ◽  
Author(s):  
T.P. Rothman ◽  
N.M. Le Douarin ◽  
J.C. Fontaine-Perus ◽  
M.D. Gershon
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Peripheral Nerves ◽  
Sympathetic Ganglia ◽  
Limb Bud ◽  
Pigment Cells ◽  
Developmental Potential ◽  
Migratory Experience ◽  
Host Embryo

The technique of back-transplantation was used to investigate the developmental potential of neural crest-derived cells that have migrated to and colonized the avian bowel. Segments of quail bowel (removed at E4) were grafted between the somites and neural tube of younger (E2) chick host embryos. Grafts were placed at a truncal level, adjacent to somites 14–24. Initial experiments, done in vitro, confirmed that crest-derived cells are capable of migrating out of segments of foregut explanted at E4. The foregut, which at E4 has been colonized by cells derived from the vagal crest, served as the donor tissue. Comparative observations were made following grafts of control tissues, which included hindgut, lung primordia, mesonephros and limb bud. Additional experiments were done with chimeric bowel in which only the crest-derived cells were of quail origin. Targets in the host embryos colonized by crest-derived cells from the foregut grafts included the neural tube, spinal roots and ganglia, peripheral nerves, sympathetic ganglia and the adrenals, but not the gut. Donor cells in these target organs were immunostained by the monoclonal antibody, NC-1, indicating that they were crest-derived and developing along neural or glial lineages. Some of the crest-derived cells (NC-1-immunoreactive) that left the bowel and reached sympathetic ganglia, but not peripheral nerves or dorsal root ganglia, co-expressed tyrosine hydroxylase immunoreactivity, a neural characteristic never expressed by crest-derived cells in the avian gut. None of the cells leaving enteric back-grafts produced pigment. Cells of mesodermal origin were also found to leave donor explants and aggregate in dermis and feather germs near the grafts. These observations indicate that crest-derived cells, having previously migrated to the bowel, retain the ability to migrate to distant sites in a younger embryo. The routes taken by these cells appear to reflect, not their previous migratory experience, but the level of the host embryo into which the graft is placed. Some of the population of crest-derived cells that leave the back-transplanted gut remain capable of expressing phenotypes that they do not express within the bowel in situ, but which are appropriate for the site in the host embryo to which they migrate.

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