The Pigment Cell System in the Light Sussex Fowl

Development ◽  
1959 ◽  
Vol 7 (3) ◽  
pp. 361-374
Author(s):  
J. Cohen
Keyword(s):  
Pigment Cell ◽  
Cell System ◽  
Pigment Cells ◽  
Black Stripe ◽  
White Feather

Light Sussex embryos and day-old chicks have no pigmentation of their plumage. Some pigmentation appears at the bases of the wing and tail primaries during the first week after hatching, and at about 6 weeks each neck feather shows a broad longitudinal medial black stripe. The saddle, flank, and breast feathers remain unpigmented, except in some strains which may show some, black flecks in these feathers as the bird ages. Thus in the adult Light Sussex the flight feathers of the wings and tail show considerable areas of black, the neck feathers have a broad black stripe on each side of the rachis, and the rest of the plumage is white (Plate 1, figs. A, B, C). The question therefore arises as to whether the pigment cells are present and non-functional, or absent, in the white feather of a partly pigmented breed such as the Light Sussex.

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.

scholarly journals Review: The Role of Wnt/β-Catenin Signalling in Neural Crest Development in Zebrafish

2021 ◽  
Vol 9 ◽  
Author(s):  
Gemma Sutton ◽  
Robert N. Kelsh ◽  
Steffen Scholpp
Keyword(s):  
Neural Crest ◽  
Pigment Cell ◽  
Model Organism ◽  
Neural Plate ◽  
The Body ◽  
Signalling Pathway ◽  
Border Region ◽  
Pigment Cells ◽  
Neural Plate Border

The neural crest (NC) is a multipotent cell population in vertebrate embryos with extraordinary migratory capacity. The NC is crucial for vertebrate development and forms a myriad of cell derivatives throughout the body, including pigment cells, neuronal cells of the peripheral nervous system, cardiomyocytes and skeletogenic cells in craniofacial tissue. NC induction occurs at the end of gastrulation when the multipotent population of NC progenitors emerges in the ectodermal germ layer in the neural plate border region. In the process of NC fate specification, fate-specific markers are expressed in multipotent progenitors, which subsequently adopt a specific fate. Thus, NC cells delaminate from the neural plate border and migrate extensively throughout the embryo until they differentiate into various cell derivatives. Multiple signalling pathways regulate the processes of NC induction and specification. This review explores the ongoing role of the Wnt/β-catenin signalling pathway during NC development, focusing on research undertaken in the Teleost model organism, zebrafish (Danio rerio). We discuss the function of the Wnt/β-catenin signalling pathway in inducing the NC within the neural plate border and the specification of melanocytes from the NC. The current understanding of NC development suggests a continual role of Wnt/β-catenin signalling in activating and maintaining the gene regulatory network during NC induction and pigment cell specification. We relate this to emerging models and hypotheses on NC fate restriction. Finally, we highlight the ongoing challenges facing NC research, current gaps in knowledge, and this field’s potential future directions.

scholarly journals Regulation of melanocyte development by ligand-dependent BMP signaling underlies oncogenic BMP signaling in melanoma

2019 ◽  
Author(s):  
Alec K. Gramann ◽  
Arvind M. Venkatesan ◽  
Melissa Guerin ◽  
Craig J. Ceol
Keyword(s):  
Neural Crest ◽  
Pigment Cell ◽  
Terminal Differentiation ◽  
Melanoma Cells ◽  
Cell Development ◽  
Bmp Signaling ◽  
Pigment Cells ◽  
Cell Type ◽  
Neural Crest Development ◽  
Direct Regulation

AbstractPreventing terminal differentiation is important in the development and progression of many cancers including melanoma. Recent identification of the BMP ligand GDF6 as a novel melanoma oncogene showed GDF6-activated BMP signaling suppresses differentiation of melanoma cells. Previous studies have identified roles for GDF6 orthologs during early embryonic and neural crest development, but have not identified direct regulation of melanocyte development by GDF6. Here, we investigate the BMP ligand gdf6a, a zebrafish ortholog of human GDF6, during the development of melanocytes from the neural crest. We establish that the loss of gdf6a or inhibition of BMP signaling during neural crest development disrupts normal pigment cell development, leading to an increase in the number of melanocytes and a corresponding decrease in iridophores, another neural crest-derived pigment cell type in zebrafish. This shift occurs as pigment cells arise from the neural crest and depends on mitfa, an ortholog of MITF, a key regulator of melanocyte development that is also targeted by oncogenic BMP signaling. Together, these results indicate that the oncogenic role ligand-dependent BMP signaling plays in suppressing differentiation in melanoma is a reiteration of its physiological roles during melanocyte development.

‘Transdifferentiation’ of chicken neural retina into lens and pigment epithelium in culture: controlling influences

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 1-21
Author(s):  
D. J. Pritchard ◽  
R. M. Clayton ◽  
D. I. De Pomerai
Keyword(s):  
Pigment Cell ◽  
Pigment Epithelium ◽  
Neural Retina ◽  
Medium Composition ◽  
Pigment Cells ◽  
Bicarbonate Concentration ◽  
Experimental Conditions ◽  
Culture Growth ◽  
New Hypothesis

The in vitro transdifferentiation of chicken embryo neural retina into pigment epithelium and lens cells was investigated under a variety of experimental conditions. Our findings suggest that some aspects of the phenomena are a function of medium composition and volume, whereas others depend upon conditions which develop during culture growth. Before melanin is visible, potential pigment cells are recognized as foci within epithelialsheets which remain in contact with the dish. The final area occupied by colonies of potential pigment cells is directly proportional to bicarbonate concentration. Low total medium volume also favours formation of potential pigment cells. In contrast the extent of cells other than potential pigment cells is not related to bicarbonate and is favoured when the volume of medium is large. Accumulation of melanin within the potential pigment cell colonies is suppressed when cells are crowded together. Lentoid bodies are formed from cells which are distinct from potential pigment cells and arise in crowded situations, in association with multilayering. Another type of structure superficially resembling a lentoid is derived from cell aggregates formed during the initial establishment of cultures. The survival of these ‘aggregate bodies’ is inversely related to bicarbonate concentration. Crystallin content is unrelated to lentoid numbers. The results provide the basis for a new hypothesis concerning cytodifferentiation in this system.

The Fine Structure of the Eye of the Leech, Helobdella Stagnalis

1967 ◽  
Vol 2 (3) ◽  
pp. 341-348
Author(s):  
A. W. CLARK
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Photoreceptor Cell ◽  
Receptor Cell ◽  
Pigment Cell ◽  
Cell Mass ◽  
Pigment Cells ◽  
Cell Cytoplasm ◽  
Receptor Cells ◽  
Intracellular Vesicle

The eye of the rhynchobdellid leech, Helobdella stagnalis, has been examined with the electron microscope. The eye is composed of a cup of pigment cells surrounding a compact mass of photo-receptor cells. In addition to pigment granules, the pigment-cell cytoplasm is characterized by mitochondria, a Golgi complex, and profiles of rough-surfaced endoplasmic reticulum. The photoreceptor cell contains a microvillous rhabdomere. The microvilli arise from the membrane of a large intracellular vesicle and obliterate much of its lumen. No connexion between the lumen of the intracellular vesicle and the extracellular space has been observed. The plasmalemma of the photoreceptor cell is folded to form thin pleats of cytoplasm which separate adjacent receptor cells from each other. No glial-like cells have been seen in the receptor cell mass. Directly subjacent to the microvilli and surrounding the intracellular vesicle is a tortuous and predominantly smooth-surfaced endoplasmic reticulum. A pair of centrioles is found near the rhabdomere. The cytoplasm around the nucleus is characterized by smooth- and rough-surfaced elements of endoplasmic reticulum, many mitochondria, and a Golgi complex. Proximally, the receptor cell narrows to form a nerve fibre which joins those from other cells to form the optic nerve.

nacre encodes a zebrafish microphthalmia-related protein that regulates neural-crest-derived pigment cell fate

Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3757-3767 ◽  
Author(s):  
J.A. Lister ◽  
C.P. Robertson ◽  
T. Lepage ◽  
S.L. Johnson ◽  
D.W. Raible
Keyword(s):  
Transcription Factor ◽  
Retinal Pigment Epithelium ◽  
Neural Crest ◽  
Cell Fate ◽  
Pigment Cell ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Pigment Cells ◽  
Evolutionary Divergence ◽  
Wild Type

We report the isolation and identification of a new mutation affecting pigment cell fate in the zebrafish neural crest. Homozygous nacre (nac(w2)) mutants lack melanophores throughout development but have increased numbers of iridophores. The non-crest-derived retinal pigment epithelium is normal, suggesting that the mutation does not affect pigment synthesis per se. Expression of early melanoblast markers is absent in nacre mutants and transplant experiments suggested a cell-autonomous function in melanophores. We show that nac(w2) is a mutation in a zebrafish gene encoding a basic helix-loop-helix/leucine zipper transcription factor related to microphthalmia (Mitf), a gene known to be required for development of eye and crest pigment cells in the mouse. Transient expression of the wild-type nacre gene restored melanophore development in nacre(−/−) embryos. Furthermore, misexpression of nacre induced the formation of ectopic melanized cells and caused defects in eye development in wild-type and mutant embryos. These results demonstrate that melanophore development in fish and mammals shares a dependence on the nacre/Mitf transcription factor, but that proper development of the retinal pigment epithelium in the fish is not nacre-dependent, suggesting an evolutionary divergence in the function of this gene.

Zebrafish Pigment Pattern Formation: Insights into the Development and Evolution of Adult Form

2019 ◽  
Vol 53 (1) ◽  
pp. 505-530 ◽  
Author(s):  
Larissa B. Patterson ◽  
David M. Parichy
Keyword(s):  
Pattern Formation ◽  
Pigment Cell ◽  
Cell Lineage ◽  
Pigment Cells ◽  
Cellular Interactions ◽  
Lineage Specification ◽  
Pigment Pattern ◽  
Adult Form ◽  
Pattern Development ◽  
Pigment Patterns

Vertebrate pigment patterns are diverse and fascinating adult traits that allow animals to recognize conspecifics, attract mates, and avoid predators. Pigment patterns in fish are among the most amenable traits for studying the cellular basis of adult form, as the cells that produce diverse patterns are readily visible in the skin during development. The genetic basis of pigment pattern development has been most studied in the zebrafish, Danio rerio. Zebrafish adults have alternating dark and light horizontal stripes, resulting from the precise arrangement of three main classes of pigment cells: black melanophores, yellow xanthophores, and iridescent iridophores. The coordination of adult pigment cell lineage specification and differentiation with specific cellular interactions and morphogenetic behaviors is necessary for stripe development. Besides providing a nice example of pattern formation responsible for an adult trait of zebrafish, stripe-forming mechanisms also provide a conceptual framework for posing testable hypotheses about pattern diversification more broadly. Here, we summarize what is known about lineages and molecular interactions required for pattern formation in zebrafish, we review some of what is known about pattern diversification in Danio, and we speculate on how patterns in more distant teleosts may have evolved to produce a stunningly diverse array of patterns in nature.

Origin and behaviour of pigment cells in sea urchin embryos

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S42-S43 ◽  
Author(s):  
Tetsuya Kominami
Keyword(s):  
Sea Urchin ◽  
Pigment Cell ◽  
Cell Lineage ◽  
Pigment Cells ◽  
Cleavage Stage ◽  
Fate Map ◽  
Blastula Stage ◽  
Cell Stage ◽  
Stage Embryo ◽  
Founder Cells

Sea urchin pluteus larvae contain dozens of pigment cells in their ectoderm. These pigment cells are the descendants of the veg2 blastomeres of the 60-cell stage embryo. According to the fate map made by Ruffins and Ettensohn, the prospective pigment cells occupy the central region of the vegetal plate. Most of these prospective pigment cells exclusively give rise to pigment cells. Therefore, specification of the pigment cell lineage should occur at some point between the 60-cell and mesenchyme blastula stage. However, the detailed process of the specification of the pigment lineage is unknown.When are pigment cells specified? Are cell interactions necessary for the specification? Do founder cells exist? To answer these questions, I treated embryos with Ca2+-free seawater during the cleavage stage and examined the number of pigment cells observed in pluteus larvae. Treatment at 5.5–8.5 h and especially 7.5–10.5 h postfertilisation markedly reduced the number of pigment cells. The decrease was statistically significant. On the other hand, the treatment at 3.5–6.5 h or 9.5–12.5 h never reduced the number of pigment cells. By examining the frequency of the appearance of embryos whose numbers of pigment cells were less than 20, it was also found that the numbers of pigment cells were frequently in multiples of 4. Embryos having 4, 8, 12, 16 and 20 pigment cells were more frequently observed. Statistics indicated that the frequency of appearance was not random. These results indicated that cell contacts are necessary for the specification of pigment cells and that the specification occurs from 7 to 10 h postfertilisation. The results also suggest that the founder cells, if they exist, divide twice before they differentiate into pigment cells.

A Peculiar Kind of Pigment Cell in the Compound Eye of Lepisma saccharina L. (Thysanura)

1973 ◽  
Vol 4 (2) ◽  
pp. 87-90 ◽  
Author(s):  
Rolf Elofsson
Keyword(s):  
Basal Lamina ◽  
Light Microscope ◽  
Compound Eye ◽  
Pigment Cell ◽  
Pigment Cells ◽  
Pigment Granules ◽  
A Cell ◽  
Lepisma Saccharina

AbstractThe ultrastructure of the primary pigment cells of the compound eye of Lepisma saccharina is described. The cells are four in number. The pigment granules are contained in fingerlike protrusions from the pigment cells. These protrusions project into the enlarged basal lamina surrounding the ommatidial top. The large basal lamina could have given the impression of a cell (called corneagen) in the light microscope.

scholarly journals Immunohistochemical analysis of pigment cell tumors in two cyprinid species

2019 ◽  
Vol 31 (5) ◽  
pp. 788-791
Author(s):  
Wesley C. Siniard ◽  
Matthew F. Sheley ◽  
Brittany N. Stevens ◽  
Christine A. Parker-Graham ◽  
Melissa A. Roy ◽  
...  
Keyword(s):  
Internal Control ◽  
Spindle Cell ◽  
Pigment Cell ◽  
Immunohistochemical Analysis ◽  
Pigment Cells ◽  
Semiquantitative Analysis ◽  
Cellular Origin ◽  
Immunohistochemical Assay ◽  
Cyprinid Species ◽  
Spindle Cell Tumors

Pigment cell tumors, also known as chromatophoromas, are cutaneous spindle cell neoplasms originating from pigment cells (chromatophores) in the dermis of teleosts, amphibians, and reptiles. Chromatophoromas share similar histologic morphology to other spindle cell tumors and are not always pigmented. Therefore, immunohistochemical analysis may be useful in distinguishing these neoplasms from tumors of other cellular origin when poorly pigmented. We performed 3 immunohistochemistry assays (PNL-2, melan A, and SOX10) on 8 cutaneous neoplasms from 8 teleosts diagnosed as chromatophoromas based on histologic morphology. Semiquantitative analysis of immunoreactivity was evaluated on each immunohistochemical assay using a 0–3 scale. PNL-2 exhibited mild-to-moderate (1 or 2) immunoreactivity in 7 of the cases, and resident chromatophores (internal control) were also immunoreactive in these cases. Melan A exhibited mild-to-moderate (1 or 2) immunoreactivity in 4 cases (and with resident chromatophores in these cases); SOX10 was not immunoreactive in any cases. Our results indicate that PNL-2 may be a useful marker in teleosts to distinguish tumors of chromatophore origin. Melan A could also be useful, but appears to be less sensitive, and SOX10 is likely not a useful marker for these neoplasms in teleosts.

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