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NTM Dec 2021
Topics: Ferrocyanides; Pigmentation
PubMed: 34491368
DOI: 10.1007/s00048-021-00311-w -
Infection Dec 2021Cydnidae bug (also termed the burrowing bug) are arthropods of the order Hemiptera, that are recognized by their morphological adaptations for digging. They release an...
Cydnidae bug (also termed the burrowing bug) are arthropods of the order Hemiptera, that are recognized by their morphological adaptations for digging. They release an odorous substance from special glands that serve as self-defense, causing pigmented macules when in contact with human skin, especially during the rainy season. Knowledge of this rarely described condition can help avoid unnecessary investigation(s).
Topics: Animals; Heteroptera; Humans; Pigmentation
PubMed: 32654020
DOI: 10.1007/s15010-020-01481-w -
ELife Jun 2021Analysing changes in hair pigmentation may lead to a better understanding of the impacts of 'life events' on human biology and aging.
Analysing changes in hair pigmentation may lead to a better understanding of the impacts of 'life events' on human biology and aging.
Topics: Aging; Hair; Hair Color; Humans; Pigmentation
PubMed: 34190044
DOI: 10.7554/eLife.70584 -
Trends in Ecology & Evolution May 2021Melanins are widespread pigments in vertebrates, with important roles in visual signaling, UV protection, and homeostasis. Fossil evidence of melanin and melanin-bearing... (Review)
Review
Melanins are widespread pigments in vertebrates, with important roles in visual signaling, UV protection, and homeostasis. Fossil evidence of melanin and melanin-bearing organelles - melanosomes - in ancient vertebrates may illuminate the evolution of melanin and its functions, but macroevolutionary trends are poorly resolved. Here, we integrate fossil data with current understanding of melanin function, biochemistry, and genetics. Mapping key genes onto phenotypic attributes of fossil vertebrates identifies potential genomic controls on melanin evolution. Taxonomic trends in the anatomical location, geometry, and chemistry of vertebrate melanosomes are linked to the evolution of endothermy. These shifts in melanin biology suggest fundamental links between melanization and vertebrate ecology. Tissue-specific and taxonomic trends in melanin chemistry support evidence for evolutionary tradeoffs between function and cytotoxicity.
Topics: Animals; Fossils; Melanins; Melanosomes; Pigmentation; Vertebrates
PubMed: 33549373
DOI: 10.1016/j.tree.2020.12.012 -
Pediatric Dermatology Nov 2022After the skin is irritated or injured, the color of the skin can change. The skin may become darker or lighter than the natural skin color. This skin color change is...
After the skin is irritated or injured, the color of the skin can change. The skin may become darker or lighter than the natural skin color. This skin color change is called postinflammatory pigment alteration. The color change is temporary but can be worrisome for families.
Topics: Humans; Pigmentation Disorders; Skin Pigmentation; Skin
PubMed: 36440999
DOI: 10.1111/pde.15203 -
Current Topics in Developmental Biology 2016In Drosophila, as well as in many other plants and animals, pigmentation is highly variable both within and between species. This variability, combined with powerful... (Review)
Review
In Drosophila, as well as in many other plants and animals, pigmentation is highly variable both within and between species. This variability, combined with powerful genetic and transgenic tools as well as knowledge of how pigment patterns are formed biochemically and developmentally, has made Drosophila pigmentation a premier system for investigating the genetic and molecular mechanisms responsible for phenotypic evolution. In this chapter, we review and synthesize findings from a rapidly growing body of case studies examining the genetic basis of pigmentation differences in the abdomen, thorax, wings, and pupal cases within and between Drosophila species. A core set of genes, including genes required for pigment synthesis (eg, yellow, ebony, tan, Dat) as well as developmental regulators of these genes (eg, bab1, bab2, omb, Dll, and wg), emerge as the primary sources of this variation, with most genes having been shown to contribute to pigmentation differences both within and between species. In cases where specific genetic changes contributing to pigmentation divergence were identified in these genes, the changes were always located in noncoding sequences and affected cis-regulatory activity. We conclude this chapter by discussing these and other lessons learned from evolutionary genetic studies of Drosophila pigmentation and identify topics we think should be the focus of future work with this model system.
Topics: Abdomen; Animals; Drosophila; Organ Specificity; Pigmentation; Pupa; Thorax; Wings, Animal
PubMed: 27282023
DOI: 10.1016/bs.ctdb.2016.03.004 -
Bio Systems Aug 2023We have reviewed and interpreted the thermodynamic principles for flower pigmentation. The basic thoughts are as follows: 1) any biological trait is associated with one...
We have reviewed and interpreted the thermodynamic principles for flower pigmentation. The basic thoughts are as follows: 1) any biological trait is associated with one thermodynamic system; 2) a thermodynamic system of biology cannot be physically isolated from complex thermal systems of biology but can be separately studied using thermodynamic methods; 3) a thermodynamic system of biology has all types of information, including volume, shape, and structure, unlike the traditional thermal system of gases; 4) a thermodynamic system of biology is associated with one type of biological structure that is not fully fixed but can change its conformation under different conditions; and 5) a thermodynamic system of biology shows a hierarchical structure. On the basis of these principles, several conclusions regarding flower pigmentation are obtained as follows: 1) processes of pigmentation formation can be divided into reversible and irreversible processes; 2) the reversible process is related to quantitative changes in pigments; 3) the irreversible process is related to the formation of stable pigmentation patterns that are physiologically inherited; 4) the spot pattern of color pigmentation represents an independent island of the physiological system; 5) many types of activators and inhibitors are involved in flower pigmentation production; 6) the patterns of flower pigmentation can be modulated; and 7) the evolution mechanism of organogenesis can be separated into several steps of independent thermodynamic processes. Our conclusion is that the thermodynamic system, rather than the dynamic system, is the essential and fundamental attribute of biological behaviors.
Topics: Pigmentation; Flowers; Phenotype; Thermodynamics
PubMed: 37277021
DOI: 10.1016/j.biosystems.2023.104938 -
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 -
Journal of the Royal Society, Interface Jul 2023Many of the world's 10 000 bird species lay coloured or patterned eggs. The large diversity of eggshell patterning among birds, achieved through pigment, has been...
Many of the world's 10 000 bird species lay coloured or patterned eggs. The large diversity of eggshell patterning among birds, achieved through pigment, has been attributed to a few selective agents such as crypsis, thermoregulation, egg recognition, mate signalling, egg strength and protecting the embryo from UV. Pigmentation may influence the texture of eggshells, which in turn may be important for dealing with water and microbes. We measured surface roughness (, nm), surface skewness () and surface kurtosis (), which describe different aspects of surface texture, across 204 bird species with maculated (patterned) eggs and 166 species with immaculate (non-patterned) eggs. Using phylogenetically controlled analyses, we tested whether maculated eggshells have different surface topography between the foreground colour and background colour, and between the background colour of maculated eggshells and the surface of immaculate eggshells. Secondly, we determined to what extent variation in eggshell pigmentation of the foreground and background colour is determined by phylogenetic relatedness, and whether certain life-history traits are important predictors of eggshell surface structure. We show that the surface of maculated eggs consists of a rougher foreground pigment compared to the background pigment across 71% of the 204 bird species (54 families) investigated. Species that lay immaculate eggs showed no difference in surface roughness, kurtosis or skewness compared to background pigment of maculated eggs. The difference in eggshell surface roughness between foreground and background pigmentation was greater among species that occupied dense habitats, such as forests with closed canopies, compared to those that nest in open and semi-open habitats (e.g. cities, deserts, grasslands, open shrubland and seashores). Among maculated eggs, foreground texture was correlated with habitat, parental care, diet, nest location, avian group and nest type, while background texture was correlated with clutch size, annual temperature, development mode and annual precipitation. Surface roughness among immaculate eggs was greatest for herbivores, and species that have larger clutch sizes. Together, this suggests that multiple life-history traits have influenced the evolution of eggshell surface textures in modern birds.
Topics: Animals; Birds; Body Temperature Regulation; Egg Shell; Phylogeny; Pigmentation
PubMed: 37434502
DOI: 10.1098/rsif.2023.0293