-
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 -
Annals of Botany Nov 2022Land plants commonly produce red pigmentation as a response to environmental stressors, both abiotic and biotic. The type of pigment produced varies among different land... (Review)
Review
BACKGROUND
Land plants commonly produce red pigmentation as a response to environmental stressors, both abiotic and biotic. The type of pigment produced varies among different land plant lineages. In the majority of species they are flavonoids, a large branch of the phenylpropanoid pathway. Flavonoids that can confer red colours include 3-hydroxyanthocyanins, 3-deoxyanthocyanins, sphagnorubins and auronidins, which are the predominant red pigments in flowering plants, ferns, mosses and liverworts, respectively. However, some flowering plants have lost the capacity for anthocyanin biosynthesis and produce nitrogen-containing betalain pigments instead. Some terrestrial algal species also produce red pigmentation as an abiotic stress response, and these include both carotenoid and phenolic pigments.
SCOPE
In this review, we examine: which environmental triggers induce red pigmentation in non-reproductive tissues; theories on the functions of stress-induced pigmentation; the evolution of the biosynthetic pathways; and structure-function aspects of different pigment types. We also compare data on stress-induced pigmentation in land plants with those for terrestrial algae, and discuss possible explanations for the lack of red pigmentation in the hornwort lineage of land plants.
CONCLUSIONS
The evidence suggests that pigment biosynthetic pathways have evolved numerous times in land plants to provide compounds that have red colour to screen damaging photosynthetically active radiation but that also have secondary functions that provide specific benefits to the particular land plant lineage.
Topics: Anthocyanins; Embryophyta; Pigmentation; Betalains; Plants; Flavonoids
PubMed: 36070407
DOI: 10.1093/aob/mcac109 -
Journal of Neuroscience Research Jan 2019Albinism, typically characterized by decreased melanin synthesis, is associated with significant visual deficits owing to developmental changes during neurosensory... (Review)
Review
Albinism, typically characterized by decreased melanin synthesis, is associated with significant visual deficits owing to developmental changes during neurosensory retina development. All albinism is caused by genetic mutations in a group of diverse genes including enzymes, transporters, G-protein coupled receptor. Interestingly, these genes are not expressed in the neurosensory retina. Further, regardless of cause of albinism, all forms of albinism have the same retinal pathology, the extent of which is variable. In this review, we explore the possibility that this similarity in retinal phenotype is because all forms of albinism funnel through the same final common pathway. There are currently seven known genes linked to the seven forms of ocular cutaneous albinism. These types of albinism are the most common, and result in changes to all pigmented tissues (hair, skin, eyes). We will discuss the incidence and mechanism, where known, to develop a picture as to how the mutations cause albinism. Next, we will examine the one form of albinism which causes tissue-specific pathology, ocular albinism, where the eye exhibits the retinal albinism phenotype despite near normal melanin synthesis. We will discuss a potential way to treat the disease and restore normal retinal development. Finally, we will briefly discuss the possibility that this same pathway may intersect with the most common cause of permanent vision loss in the elderly.
Topics: Albinism, Ocular; Eye Proteins; Humans; Melanins; Membrane Glycoproteins; Mutation; Pigmentation; Retina; Retinal Pigment Epithelium
PubMed: 29761529
DOI: 10.1002/jnr.24246 -
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 -
Biology Letters Aug 2021Pterins are one of the major sources of bright coloration in animals. They are produced endogenously, participate in vital physiological processes and serve a variety of...
Pterins are one of the major sources of bright coloration in animals. They are produced endogenously, participate in vital physiological processes and serve a variety of signalling functions. Despite their ubiquity in nature, pterin-based pigmentation has received little attention when compared to other major pigment classes. Here, we summarize major aspects relating to pterin pigmentation in animals, from its long history of research to recent genomic studies on the molecular mechanisms underlying its evolution. We argue that pterins have intermediate characteristics (endogenously produced, typically bright) between two well-studied pigment types, melanins (endogenously produced, typically cryptic) and carotenoids (dietary uptake, typically bright), providing unique opportunities to address general questions about the biology of coloration, from the mechanisms that determine how different types of pigmentation evolve to discussions on honest signalling hypotheses. Crucial gaps persist in our knowledge on the molecular basis underlying the production and deposition of pterins. We thus highlight the need for functional studies on systems amenable for laboratory manipulation, but also on systems that exhibit natural variation in pterin pigmentation. The wealth of potential model species, coupled with recent technological and analytical advances, make this a promising time to advance research on pterin-based pigmentation in animals.
Topics: Animals; Carotenoids; Pigmentation; Pterins
PubMed: 34403644
DOI: 10.1098/rsbl.2021.0221 -
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 -
Medicina Oral, Patologia Oral Y Cirugia... May 2022The diagnosis of oral melanotic lesions is, more often than not, challenging in the clinical practice due to the fact that there are several reasons which may cause an... (Review)
Review
BACKGROUND
The diagnosis of oral melanotic lesions is, more often than not, challenging in the clinical practice due to the fact that there are several reasons which may cause an increase in pigmentation on localized or generalized areas. Among these, medication stands out.
MATERIAL AND METHODS
In this work, we have carried out a review in the reference pharma database: Micromedex® followed by a review of the scientific published literature to analyse coincidences and possible discrepancies.
RESULTS
Our findings show that there are several prescription drugs that can cause pigmented lesions in the oral mucosa. This must be known by clinicians in order to properly diagnose pigmented lesions. We have identified a set of 21 medicaments which cause these lesions, some of which are used frequently in the clinic, such as Metronidazole, Amitriptyline, conjugated oestrogens and Chlorhexidine gluconate. We also found discrepancies with the data published in specialized literature, some of which wasn't reflected in the Summary of Product Characteristics.
CONCLUSIONS
Our work highlights the importance of the proper communication of adverse drug reactions (ADR) by health professionals in order to provide thorough and accurate information and diagnosis.
Topics: Humans; Mouth Mucosa; Oral Ulcer; Pigmentation
PubMed: 35420067
DOI: 10.4317/medoral.25110 -
American Journal of Physiology.... Sep 2019The vitamin D-folate hypothesis has been proposed as an explanation for the evolution of human skin pigmentation. According to this hypothesis, a darkened skin pigment... (Review)
Review
The vitamin D-folate hypothesis has been proposed as an explanation for the evolution of human skin pigmentation. According to this hypothesis, a darkened skin pigment was adapted by early human populations living in equatorial Africa to protect against photodegradation of bioavailable folate by ultraviolet radiation (UVR). As humans moved away from the equator to more northern latitudes and occupied regions of lower UVR exposure and greater seasonal variation, however, depigmentation occurred to allow for adequate biosynthesis of vitamin D. Vitamin D and folate are both recognized for their evolutionary importance in healthy pregnancy and early childhood development. More recently, evidence has emerged demonstrating the importance of both vitamin D and folate in vascular health via their effects in reducing oxidative stress and improving nitric oxide (NO) bioavailability. Thus, populations with darkened skin pigmentation may be at elevated risk of vascular dysfunction and cardiovascular disease in low UVR environments due to hypovitaminosis D; particularly important as darkly-pigmented African-Americans represent an at-risk population for cardiovascular disease. Conversely, lightly pigmented populations in high UVR environments may be at risk of deleterious vascular effects of UVR-induced folate degradation. The focus of this review is to explore the currently available literature regarding the potential role of UVR in vascular health via its differential effects on vitamin D and folate metabolism, as well as the interaction between skin pigmentation, genetics, and environment in modulating the vascular influence of UVR exposure.
Topics: Biological Evolution; Cardiovascular Diseases; Folic Acid; Humans; Skin Pigmentation; Ultraviolet Rays; Vitamin D
PubMed: 31314544
DOI: 10.1152/ajpregu.00136.2019 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Jun 2021Since synthetic pigments are potentially harmful to human health, natural ones such as bixin, one of the carotenoids, are favored. As the second widely used natural... (Review)
Review
Since synthetic pigments are potentially harmful to human health, natural ones such as bixin, one of the carotenoids, are favored. As the second widely used natural pigment in the world, there is significant interest in the biosynthetic pathway of bixin which has not been fully elucidated. This review summarizes the chemical properties, extraction methods, biosynthetic pathway and application of bixin. In addition, we compared the difference between traditional extraction methods and new extraction techniques. Moreover, we described the genes involved in the biosynthetic pathway of bixin and the effects of abiotic stress on the biosynthesis of bixin, and discussed the application of bixin in food, pharmaceutical and chemical industries. However, the researches on bixin biosynthesis pathway are mostly carried out at the transcriptome level and most of the gene functions have not been elucidated. Therefore, we propose to characterize the entire bixin biosynthetic pathway using techniques of genomics, bioinformatics, and phytochemistry. This will help facilitate the synthetic biology research of bixin and development of bixin into new drugs.
Topics: Bixaceae; Carotenoids; Humans; Pigmentation; Transcriptome
PubMed: 34227289
DOI: 10.13345/j.cjb.200724