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Head and Neck Pathology Mar 2019Black and brown pigmentation of the oral mucosa can occur due to a multitude of non-neoplastic causes. Endogenous or exogenous pigments may be responsible for oral... (Review)
Review
Black and brown pigmentation of the oral mucosa can occur due to a multitude of non-neoplastic causes. Endogenous or exogenous pigments may be responsible for oral discoloration which can range from innocuous to life-threatening in nature. Physiologic, reactive, and idiopathic melanin production seen in smoker's melanosis, drug-related discolorations, melanotic macule, melanoacanthoma and systemic diseases are presented. Exogenous sources of pigmentation such as amalgam tattoo and black hairy tongue are also discussed. Determining the significance of mucosal pigmented lesions may represent a diagnostic challenge for clinicians. Biopsy is indicated whenever the source of pigmentation cannot be definitively identified based on the clinical presentation.
Topics: Humans; Mouth Diseases; Mouth Mucosa; Pigmentation; Pigmentation Disorders
PubMed: 30671761
DOI: 10.1007/s12105-018-0980-9 -
Current Opinion in Genetics &... Aug 2021The order Odonata (dragonflies and damselflies) comprises diurnal insects with well-developed vision, showing diverse colors in adult wings and bodies. It is one of the... (Review)
Review
The order Odonata (dragonflies and damselflies) comprises diurnal insects with well-developed vision, showing diverse colors in adult wings and bodies. It is one of the most ancestral winged insect groups. Because Odonata species use visual cues to recognize each other, color patterns have been investigated from ecological and evolutionary viewpoints. Here we review the recent progress on molecular mechanisms of pigmentation, especially focused on light-blue coloration. Results from histology and pigment analysis showed that ommochrome pigments on the proximal layer and pteridine pigments on the distal layer of the epidermis are essential for light-blue coloration. We also summarize genes involved in the biosynthesis of three major insect pigments conserved across insects and discuss that gene-functional analysis deserves future studies.
Topics: Animals; Color; Odonata; Phenothiazines; Phenotype; Pigmentation; Wings, Animal
PubMed: 33482606
DOI: 10.1016/j.gde.2020.12.014 -
Development, Growth & Differentiation Jun 2020Fruit flies (Drosophila and its close relatives, or "drosophilids") are a group that includes an important model organism, Drosophila melanogaster, and also very diverse... (Review)
Review
Fruit flies (Drosophila and its close relatives, or "drosophilids") are a group that includes an important model organism, Drosophila melanogaster, and also very diverse species distributed worldwide. Many of these species have black or brown pigmentation patterns on their wings, and have been used as material for evo-devo research. Pigmentation patterns are thought to have evolved rapidly compared with body plans or body shapes; hence they are advantageous model systems for studying evolutionary gains of traits and parallel evolution. Various groups of drosophilids, including genus Idiomyia (Hawaiian Drosophila), have a variety of pigmentations, ranging from simple black pigmentations around crossveins to a single antero-distal spot and a more complex mottled pattern. Pigmentation patterns are sometimes obviously used for sexual displays; however, in some cases they may have other functions. The process of wing formation in Drosophila, the general mechanism of pigmentation formation, and the transport of substances necessary for pigmentation, including melanin precursors, through wing veins are summarized here. Lastly, the evolution of the expression of genes regulating pigmentation patterns, the role of cis-regulatory regions, and the conditions required for the evolutionary emergence of pigmentation patterns are discussed. Future prospects for research on the evolution of wing pigmentation pattern formation in drosophilids are presented, particularly from the point of view of how they compare with other studies of the evolution of new traits.
Topics: Animals; Biological Evolution; Drosophila melanogaster; Gene Expression Regulation, Developmental; Pigmentation; Wings, Animal
PubMed: 32171022
DOI: 10.1111/dgd.12661 -
Journal of Natural Medicines Jan 2020Carotenoids are tetraterpene pigments that are distributed in photosynthetic bacteria, some species of archaea and fungi, algae, plants, and animals. About 850 naturally... (Review)
Review
Carotenoids are tetraterpene pigments that are distributed in photosynthetic bacteria, some species of archaea and fungi, algae, plants, and animals. About 850 naturally occurring carotenoids had been reported up until 2018. Photosynthetic bacteria, fungi, algae, and plants can synthesize carotenoids de novo. Carotenoids are essential pigments in photosynthetic organs along with chlorophylls. Carotenoids also act as photo-protectors, antioxidants, color attractants, and precursors of plant hormones in non-photosynthetic organs of plants. Animals cannot synthesize carotenoids de novo, and so those found in animals are either directly accumulated from food or partly modified through metabolic reactions. So, animal carotenoids show structural diversity. Carotenoids in animals play important roles such precursors of vitamin A, photo-protectors, antioxidants, enhancers of immunity, and contributors to reproduction. In the present review, I describe the structural diversity, function, biosyntheses, and metabolism of natural carotenoids.
Topics: Animals; Carotenoids; Fungi; Pigmentation; Plants
PubMed: 31588965
DOI: 10.1007/s11418-019-01364-x -
Methods in Molecular Biology (Clifton,... 2023The ommochrome and porphyrin body pigments that give freshwater planarians their brown color are produced by specialized dendritic cells located just beneath the...
The ommochrome and porphyrin body pigments that give freshwater planarians their brown color are produced by specialized dendritic cells located just beneath the epidermis. During embryonic development and regeneration, differentiation of new pigment cells gradually darkens newly formed tissue. Conversely, prolonged light exposure ablates pigment cells through a porphyrin-based mechanism similar to the one that causes light sensitivity in rare human disorders called porphyrias. Here, we describe a novel program using image-processing algorithms to quantify relative pigment levels in live animals and apply this program to analyze changes in bodily pigmentation induced by light exposure. This tool will facilitate further characterization of genetic pathways that affect pigment cell differentiation, ommochrome and porphyrin biosynthesis, and porphyrin-based photosensitivity.
Topics: Animals; Humans; Planarians; Pigmentation; Phenothiazines; Porphyrins
PubMed: 37428383
DOI: 10.1007/978-1-0716-3275-8_16 -
Trends in Genetics : TIG May 2010Animal coloration is a powerful model for studying the genetic mechanisms that determine phenotype. Genetic crosses of laboratory mice have provided extensive... (Review)
Review
Animal coloration is a powerful model for studying the genetic mechanisms that determine phenotype. Genetic crosses of laboratory mice have provided extensive information about the patterns of inheritance and pleiotropic effects of loci involved in pigmentation. Recently, the study of pigmentation genes and their functions has extended into wild populations, providing additional evidence that pigment gene function is largely conserved across disparate vertebrate taxa and can influence adaptive coloration, often in predictable ways. These new and integrative studies, along with those using a genetic approach to understand color perception, raise some important questions. Most notably, how does selection shape both phenotypic and genetic variation, and how can we use this information to further understand the phenotypic diversity generated by evolutionary processes?
Topics: Animals; Biological Evolution; Color Perception; Pigmentation
PubMed: 20381892
DOI: 10.1016/j.tig.2010.02.002 -
Revue Belge de Medecine Dentaire 2008The pigmentation is the physiological or pathological accumulation of a pigment in a tissue. Physiological pigmentation in gingiva which is a part of masticatory mucous... (Review)
Review
The pigmentation is the physiological or pathological accumulation of a pigment in a tissue. Physiological pigmentation in gingiva which is a part of masticatory mucous membranes depends on the activity of the melanocytes. These non keratinocytic cells include the melanosoma where an endogenous pigment, the melanin, is synthesized. Quantitative or qualitative disruption of mucous pigmentation leads to the apparition of pigmented lesions. When melanocytes are directly concerned, the lesions can be of intrinsic origin, such as oral mucosa melanoma, the nevus, pigmented oral lichen planus etc. Pigmented lesions can be also of extrinsic origin caused by medicaments, dental materials, tobacco etc. In this article, gingival pigmentations are described to allow practitioner to elaborate a differential and positive diagnosis of gingival pigmented lesions and to facilitate an early detection of these lesions particularly the gingival melanoma.
Topics: Diagnosis, Differential; Gingiva; Gingival Diseases; Gingival Neoplasms; Humans; Hyperpigmentation; Melanoma; Nevus; Pigmentation
PubMed: 18754536
DOI: No ID Found -
Journal of Esthetic and Restorative... Sep 2022To evaluate prevalence, distribution, intensity and extent of physiologic gingival melanin pigmentation (GMP) in black individuals.
OBJECTIVE
To evaluate prevalence, distribution, intensity and extent of physiologic gingival melanin pigmentation (GMP) in black individuals.
MATERIALS AND METHODS
For this cross-sectional study, GMP was evaluated on digital images by three calibrated examiners, according to de Krom (distribution), DOPI (intensity) and Melanin Index (extent) classifications. Descriptive statistics, Wilcoxon, Mann-Whitney, Kruskal-Wallis, Two-way ANOVA, chi square, and K-means cluster analysis were used.
RESULTS
Seventy participants were recruited. The most prevalent GMP categories were: de Krom category 2 (34.3%), DOPI heavy intensity (57.2%), and Melanin index Degree IV (50%). Significant inter-group differences were found for age (p < 0.05) but not gender (p > 0.05). Significant correspondence/overlap was observed between classifications (p > 0.05). Three GMP clusters were identified: Cluster 1 (27%; n = 19) had mild asymmetric and interspersed pigmentation; Cluster 2 (46%; n = 32) had heavy pigmentation in one long continuous ribbon, with pink marginal gingiva; and Cluster 3 (27%; n = 19) had heavy pigmentation in one long continuous ribbon, symmetric, and uniform.
CONCLUSIONS
There may be overlap among GMP classification systems. In black individuals, the predominant GMP presentation is one of a broad zone of heavily pigmented attached gingiva, in a continuous strip from central incisors to canines, symmetrical across the midline, and with pink free marginal gingiva.
CLINICAL RELEVANCE
This is the first study to analyze distribution, intensity, and extent of gingival melanin pigmentation in the same population and to integrate the various classification systems through cluster analysis. The novel findings provide a foundation for patient assessment and counseling and for future studies.
Topics: Cross-Sectional Studies; Gingiva; Gingival Diseases; Humans; Melanins; Pigmentation
PubMed: 34825763
DOI: 10.1111/jerd.12846 -
Evolution; International Journal of... Mar 2022Phenotypic plasticity is predicted to evolve in environmentally variable habitats, or those experiencing a high frequency of strong selection. The evolution of...
Phenotypic plasticity is predicted to evolve in environmentally variable habitats, or those experiencing a high frequency of strong selection. The evolution of plasticity may however be constrained by costs or physiological limitations. In flowers, UV-absorbing pigmentation ameliorates UV damage to pollen, and is linked with elevated UV exposure. Whether plasticity contributes to this pattern remains unclear. Petals of Argentina anserina have larger UV-absorbing petal areas at high elevations where they experience higher and more variable UV exposure than low elevations. We measured UV-induced pigmentation plasticity in high- and low-elevation populations (hereafter, "high," "low"), and selection on pigmentation via male fitness. We dissected UV pigment biochemistry using metabolomics to explore biochemical mechanisms underlying plasticity. High displayed positive UV-induced pigmentation plasticity but low lacked plasticity. Selection favored elevated pigmentation under UV in high, supporting adaptive plasticity. In high, UV absorption was conferred by flavonoids produced in one flavonoid pathway branch. However, in low, UV absorption was associated with many compounds spanning multiple branches. Elevated plasticity was thus associated with reduced pigment diversity. These results are consistent with adaptive floral pigmentation plasticity in more extreme and variable environments. We discuss how biochemical underpinnings of pigmentation may permit or constrain the evolution of pigmentation plasticity.
Topics: Adaptation, Physiological; Flavonoids; Flowers; Pigmentation; Pollen
PubMed: 35038345
DOI: 10.1111/evo.14422 -
Wiley Interdisciplinary Reviews.... 2009Extensive studies of the biology of the pigment-producing cell (melanocyte) have resulted in a wealth of knowledge regarding the genetics and developmental mechanisms... (Review)
Review
Extensive studies of the biology of the pigment-producing cell (melanocyte) have resulted in a wealth of knowledge regarding the genetics and developmental mechanisms governing skin and hair pigmentation. The ease of identification of altered pigment phenotypes, particularly in mouse coat color mutants, facilitated early use of the pigmentary system in mammalian genetics and development. In addition to the large collection of developmental genetics data, melanocytes are of interest because their malignancy results in melanoma, a highly aggressive and frequently fatal cancer that is increasing in Caucasian populations worldwide. The genetic programs regulating melanocyte development, function, and malignancy are highly complex and only partially understood. Current research in melanocyte development and pigmentation is revealing new genes important in these processes and additional functions for previously known individual components. A detailed understanding of all the components involved in melanocyte development and function, including interactions with neighboring cells and response to environmental stimuli, will be necessary to fully comprehend this complex system. The inherent characteristics of pigmentation biology as well as the resources available to researchers in the pigment cell community make melanocytes an ideal cell type for analysis using systems biology approaches. In this review, the study of melanocyte development and pigmentation is considered as a candidate for systems biology-based analyses.
Topics: Animals; Gene Regulatory Networks; Humans; Melanocytes; Metabolic Networks and Pathways; Pigmentation; Systems Biology
PubMed: 20161540
DOI: 10.1002/wsbm.20