Multiple Pigment Research Articles

Identification of the silkworm quail gene reveals a crucial role of a receptor guanylyl cyclase in larval pigmentation

Diverse color patterns on the integument of lepidopteran larvae play important roles in their survival through camouflage, mimicry, sexual signaling, and aposematism. In the silkworm Bombyx mori, many color pattern variations have been preserved in inbred strains making them a good model for elucidating the molecular mechanisms that underlie color pattern formation. In this study, we focused on the silkworm quail (q) mutant, which exhibits abnormalities in multiple pigment biosynthesis pathways. Positional cloning of the q gene revealed that disruption of a guanylyl cyclase gene, BmGC-I, is responsible for its abnormal pigmentation. In q mutants, we identified a 16-bp deletion in the BmGC-I transcript, resulting in the production of a premature stop codon. Knockout of the BmGC-I gene resulted in the q-like abnormal pigmentation, thereby demonstrating that the BmGC-I gene is involved in the pigment biosynthesis pathway in the integument. Moreover, quantitative reverse transcription polymerase chain reaction showed that BmGC-I was strongly expressed in the fourth instar on day 2. Our results suggest that BmGC-I deficiency affects the pigment biosynthesis pathway, which supports the involvement of guanylyl cyclase in larval coloration.

Case studies of two related Chinese patients with Carney complex presenting with extensive cardiac myxomas and PRKAR1A gene mutation of c.491_492delTG

Carney complex is an autosomal dominant disease that is clinically characterized by cardiac myxomas, spotty skin pigmentation, and endocrine overactivity. Carney complex is most commonly caused by mutations in the PRKAR1A gene on chromosome 17q22-24. Currently, there are at least 117 pathogenic mutations in PRKAR1A that have been identified. Herein, we report on two cases of Carney complex in related Chinese patients with a c.491_492delTG mutation that presented with multiple and extensive cardiac myxomas and skin pigmentation.

Intraocular juvenile xanthogranuloma masquerading as conjunctivitis in an adult

A 22-year-old female presented to us with redness, pain and intermittent blurring of vision in the left eye of one month duration. She had been diagnosed as a case of conjunctivitis elsewhere for which she was being treated with topical antibiotics. Examination of the anterior segment revealed diffuse conjunctival congestion, the presence of an inferonasal iris bulge and a streak of hyphema. Ultrasound biomicroscopy revealed an irregular echogenic mass lesion in the iris extending into the ciliary body. Fine needle aspiration cytology revealed the presence of large giant cells with multiple nuclei and pigments in the cytoplasm suggestive of Touton giant cells and multiple histiocytes confirming the diagnosis of juvenile xanthogranuloma. The patient was prescribed oral and topical steroids and the lesion resolved. Juvenile xanthogranuloma can masquerade as conjunctivitis and simple aspiration cytology can be helpful in establishing the diagnosis instead of a more invasive incision or excision biopsy.

Context-dependent relationships between multiple sexual pigments and paternal effort

Elaborately ornamented males may provide more paternal services than less ornamented males in some contexts but may alternatively invest in territoriality or mating over paternal effort. Two outstanding questions involve whether different types of sexual pigmentation communicate distinct information about paternal strategy and whether highly ornamented males adjust paternal effort to context-dependent benefits. In yellow warblers (Setophaga petechia), we explored whether carotenoid- and phaeomelanin-based pigmentation show distinct or complementary relationships to paternal effort and song rate and how males differing in pigmentation adjust behavior to nesting stage, brood size, and territorial challenge. Past studies have suggested that highly melanic male yellow warblers invest in territoriality or mating over paternal effort. However, genetic paternity data from our population indicate that males with high levels of both pigment types retain within-pair paternity but gain little extrapair paternity. Therefore, we predicted that these males should also exhibit higher paternal effort. Highly melanic males sang at high rates during incubation and provisioned incubating females at relatively low rates late in the incubation stage, but showed high late-stage nestling provisioning effort, and did not greatly reduce nestling provisioning rate under territorial challenge. Moreover, as predicted based on genetic paternity data, the relationship between melanin pigmentation and paternal effort varied with the level of carotenoid pigmentation expressed by males, with males expressing high levels of both pigment types provisioning late-stage nestlings at enhanced rates. Thus, the pigment types in combination may signal paternal benefits, and results suggest flexible investment in paternal effort by highly pigmented males.

Intravitreal Recombinant Tissue Plasminogen Activator Without Gas Injection in a Patient with Massive Submacular Hemorrhage Associated with Age-Related Macular Degeneration: A Case Report

Introduction: Submacular hemorrhage (SMH) is a leading cause of severe visual loss. Pneumatic displacement of SMH from the macular area using intravitreal injection of tissue plasminogen activator (tPA) and gas and vitrectomy with subretinal injection of tPA and intravitreal injection of gas have recently been used as the standard therapies for SMH patients. However, little has been reported on single intravitreal administration of tPA for SMH patients. Case report: A 62-year-old male patient noted both blurred vision in his left eye and difficulty speaking (dysarthria) 1 day before admission. He was diagnosed with both massive SMH and cerebral infarction. Funduscopy revealed that the fovea was shifted to the inferonasal side due to a massive subretinal blood clot, and optical coherence tomography (OCT) revealed steep retinal detachment, hyper-reflective material representing a blood clot under the retina, and multiple large retinal pigment epithelial detachments (PEDs). The patient received a single intravitreal administration of tissue plasminogen activator. After vitreous injection, nearly all of the massive subretinal blood clot moved to the peripheral retina, and the fovea returned to the appropriate position. His best corrected visual acuity improved from 20/250 to 20/100. Conclusion: The present study showed a favorable outcome of a patient with a massive SMH complicated by cerebral infarction after receiving a single intravitreal administration of tPA. We hope that the single intravitreal administration of tPA can be applied for SMH patients who are not appropriate for surgery.

Control of shell pigmentation by secretory tubules in the abalone mantle

Molluscan shells exhibit a wide diversity of pigmentation patterns and are often used as models for understanding the mechanisms underlying biological pattern formation. Numerous mathematical models have been put forward to describe these patterns, but all rely on assumptions regarding the nature of the pigments and the cells from which they are secreted. We investigated pigmentation and cellular morphology of the mantle (shell-secreting organ) of the tropical abalone, Haliotis asinina, as a crucial step towards understanding the molecular mechanisms of shell patterning in this gastropod mollusc. Accumulation and release of pigmented products occurs within secretory tubules in the prismatic zone of the juvenile H. asinina mantle. The colour observed within these tubules closely matches the colour deposited most recently within the shell lying directly above. The pigments are autofluorescent, and confocal microscopy reveals that multiple pigments can be present within a single tubule at any one time. Examination of mantle morphology in other gastropods reveals that mantle tubules are not restricted to abalone, but are not universal. The presence of a tubule-based secretory system within the abalone mantle demonstrates that pigmentation is not controlled by a simple line of cells. Instead, co-ordination of patterning events is likely to be modular, with signals received by individual cells being transmitted throughout the entire tubule to synchronise the accumulation and secretion of pigmented material.

Pseudomelanosis duodeni in a female adult with chronic renal failure

Summary Pseudomelanosis duodeni is a rare endoscopic finding that manifests as dark speckled spots in the duodenum. It is considered a benign condition and is associated with certain diseases and the use of certain medications. This study reports a case of a 74-year-old woman, with end-stage renal disease under maintenance hemodialysis, hypertension under regular medical control, iron deficiency anemia under oral iron supplement, and progressive anemia with suspicious occult gastrointestinal bleeding. Upper gastrointestinal endoscopy revealed multiple tiny brownish-black pigmentation throughout the proximal second portion of the duodenum. The histopathological examination showed pigment-laden macrophages with positive iron stain and negative melanin stain in the lamina propria of the mucosal villi.

Sedimentary pigments as indicators of cyanobacterial dynamics in a hypereutrophic lake

Lac Saint-Augustin is an urban lake located on the outskirts of Quebec City, one of North America’s oldest cities. Anthropogenic inputs from land clearing, agriculture, highway development and urbanization in the surrounding catchment have resulted in strong impacts on the limnology of the lake throughout the past three centuries. In recent years, this lake has experienced severe eutrophication, including persistent cyanobacterial blooms. In winter 2011, a sediment core was extracted from the deepest area of the lake. A detailed paleopigment analysis was used to assess eutrophication processes in the lake and to determine the timing and appearance of cyanobacterial blooms and their subsequent variability. Extracted chlorophyll a, its degradation products and 11 carotenoid pigments were identified and quantified via reverse-phase high performance liquid chromatography to examine relative changes in the phytoplankton. The results revealed large variations in the phytoplankton community structure of Lac Saint-Augustin over the past 356 years. Chlorophyll a concentrations per unit organic matter (OM) increased significantly from the base of the core to present day, rising more than 15-fold from 18.4 µg (g OM)−1 at the base of the core to 287 µg (g OM)−1 in the most recent strata. Biostratigraphical analysis revealed three major periods of enrichment, with episodes of cyanobacterial abundance from the 1890s onwards. The greatest changes occurred in the most recent period (from the 1960s to the present) relative to earlier periods, with pigment increases for all phytoplankton groups. The cyanobacterial pigments canthaxanthin, echinenone and zeaxanthin (also a marker for green algae) showed concentrations in the surface sediments that were significantly above values at the bottom of the core, and these differences were large, even giving consideration to the lesser pigment degradation near the surface. Overall, the results indicate that cyanobacterial blooms are not a recent feature of Lac Saint-Augustin but began to occur soon after catchment modification 150 years ago. The pigment records also imply that cyanobacterial and associated algal populations have risen to unprecedented levels over the last few decades of ongoing development of the Lac Saint-Augustin catchment. This study highlights the utility of multiple pigment analysis of lake sediments for identifying the timing and magnitude of anthropogenic impacts.

Multiple sexual pigments, assortative social pairing, and genetic paternity in the yellow warbler (Setophaga petechia)

In socially monogamous species, extra-pair paternity may increase the reproductive success of highly ornamented males, mediating the evolution of sexual ornaments. However, ornaments may also attract social mates, and a tradeoff between extra-pair paternity (EPP) and within-pair paternity (WPP) may complicate mating strategies. Further, in many socially monogamous species, females are also ornamented, and the relationship between female ornamentation and patterns of EPP has been neglected. We investigated the patterns of genetic paternity with respect to carotenoid- and melanin-based pigmentation in yellow warblers (Setophaga petechia) of both sexes. We asked whether males face tradeoffs between EPP and WPP, how paternity patterns relate to carotenoid- versus melanin-based pigmentation, and whether less EPP occurs in broods when males and females are assortatively paired. Males faced a tradeoff between EPP and WPP. Moreover, non-additive relationships existed between paternity patterns and the two pigment types in both sexes. Males with high melanin coverage but dull carotenoid pigmentation achieved EPP but lost WPP, whereas males with high levels of both pigment types had high WPP but gained little EPP. A parallel pattern occurred in females. Warblers paired assortatively by pigmentation and EPP was less common in broods when the sexes were assortatively paired by carotenoid pigmentation. Results suggest that the most colorful birds obtain high quality social mates and advance reproductive success through WPP, show that correlations can arise between female ornamentation and patterns of EPP, and also uniquely suggest that social pairing patterns may influence extra-pair mating strategies.

Multiple retinal pigment epithelial detachments: A case report

Case reportA 47-year-old female who presented with a bilateral idiopathic multiple pigment epithelial detachment (PED) in a routine visit. This pathology is shown as a rare clinical manifestation, where the outcome is resolution of localized atrophy of the pigment epithelium, with a good functional prognosis. DiscussionPED is a common clinical manifestation in several chorioretinal diseases, particularly in macular degeneration associated with age. Idiopathic PED can be considered as a kind of central type II serous chorioretinopathy. Fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) are complementary tests to study the number, extension, and nature of these PED.

Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata).

The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

Control of shell pigmentation by secretory tubules in the abalone mantle

Molluscan shells exhibit a wide diversity of pigmentation patterns and are often used as models for understanding the mechanisms underlying biological pattern formation. Numerous mathematical models have been put forward to describe these patterns, but all rely on assumptions regarding the nature of the pigments and the cells from which they are secreted. We investigated pigmentation and cellular morphology of the mantle (shell-secreting organ) of the tropical abalone, Haliotis asinina, as a crucial step towards understanding the molecular mechanisms of shell patterning in this gastropod mollusc. Accumulation and release of pigmented products occurs within secretory tubules in the prismatic zone of the juvenile H. asinina mantle. The colour observed within these tubules closely matches the colour deposited most recently within the shell lying directly above. The pigments are autofluorescent, and confocal microscopy reveals that multiple pigments can be present within a single tubule at any one time. Examination of mantle morphology in other gastropods reveals that mantle tubules are not restricted to abalone, but are not universal. The presence of a tubule-based secretory system within the abalone mantle demonstrates that pigmentation is not controlled by a simple line of cells. Instead, co-ordination of patterning events is likely to be modular, with signals received by individual cells being transmitted throughout the entire tubule to synchronise the accumulation and secretion of pigmented material.

Isolated Multiple Pigment Epithelial Detachments with Unknown Cause

There are many etiological factors that have led to the development of retinal pigment epithelial detachment (PED). In this paper, we have reported a patient with isolated multiple PEDs. Based on this fact, this paper aimed to give an overview of the causes of PEDs.

Eruptive pigmented patches in a patient with HIV infection under HAART

Introduction: Highly active antiretroviral therapy (HAART) is a standard treatment for HIV-infected patients. It has been reported that emtricitabine rarely induces skin pigmentation in the palms and soles. We herein report a Japanese case which presented a number of small pigmented patches on the acral sites. Main observation: A 58-year-old Japanese man complained about multiple brownish skin pigmentations on his both palms and soles after 2 months of HAART therapy. Dermatoscopic observation showed a homogeneous light brown pattern. In spite of continuance of HAART, these lesions spontaneously regressed within 11 months. Conclusion: We should know about the eruptive pigmented patches as an adverse effect under HAART with HIV infected patients.

A case of levocetirizine-induced fixed drug eruption and cross-reaction with piperazine derivatives

Fixed drug eruption is an uncommon adverse drug reaction caused by delayed cell-mediated hypersensitivity. Levocetirizine is an active (R)-enatiomer of cetirizine and there have been a few reports of fixed drug eruption related to these antihistamines. We experienced a case of levocetirizine-induced fixed drug eruption and cross-reaction with other piperazine derivatives confirmed by patch test. A 73-year-old female patient presented with recurrent generalized itching, cutaneous bullae formation, rash and multiple pigmentation at fixed sites after taking drugs for common cold. She took bepotastine besilate (Talion®) and levocetirizine (Xyzal®) as antihistamine. She took acetaminophen, pseudoephedrine 60 mg / triprolidine 2.5 mg (Actifed®), dihydrocodeinebitartrate 5 mg / di-methylephedrine hydrochloride 17.5 mg / chlorpheniramine maleate 1.5 mg / guaifenesin 50 mg (Codening®) and aluminium hydroxide 200 mg / magnesium carbonate 120 mg (Antad®) at the same time. Patch test was done with suspected drugs and the result was positive with levocetirizine. We additionally performed patch test for other antihistamines such as cetirizine, hydroxyzine, fexofenadine and loratadine. Piperazine derivatives (cetirizine and hydroxyzine) were positive, but piperidine derivatives (fexofenadine and loratadine) were negative to patch test. There was no adverse drug reaction when she was challenged with fexofenadine. We report a case of levocetirizine-induced fixed drug eruption confirmed by patch test. Cross-reactions were only observed in the piperazine derivatives and piperidine antihistamine was tolerant to the patient.

Principal Component Analysis of Multi-Pigment Scenario in Full-Color Electrophoretic Display

In this paper, we present a methodology to characterize the colorimetric performance of a full-color electrophoretic display (EPD) with multiple pigment formation. We use the principal component analysis to formulate the composite hybrid color-mixing system by using a single eigen-spectral component for each sub-pixel channel. Proposed model was validated to predict the chromatic features with high accuracy (ΔE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AVE_CIEDE2000</sub> <;0.2) for both micro-cup type and micro-encapsulated type EPD samples. This study is effective to uncover the underlying physical features from only colorant-mixture information in a novel color system.

Bimodal Intramolecular Excitation Energy Transfer in a Multichromophore Photosynthetic Model System: Hybrid Fusion Proteins Comprising Natural Phycobilin- and Artificial Chlorophyll-Binding Domains

The phycobilisomes of cyanobacteria and red-algae are highly efficient peripheral light-harvesting complexes that capture and transfer light energy in a cascade of excitation energy transfer steps through multiple phycobilin chromophores to the chlorophylls of core photosystems. In this work, we focus on the last step of this process by constructing simple functional analogs of natural phycobilisome-photosystem complexes that are based on bichromophoric protein complexes comprising a phycobilin- and a chlorophyll- or porphyrin-binding domain. The former is based on ApcE(1-240), the N-terminal chromophore-binding domain of the phycobilisome's L(CM) core-membrane linker, and the latter on HP7, a de novo designed four-helix bundle protein that was originally planned as a high-affinity heme-binding protein, analogous to b-type cytochromes. We fused a modified HP7 protein sequence to ApcEΔ, a water-soluble fragment of ApcE(1-240) obtained by excising a putative hydrophobic loop sequence of residues 77-153. HP7 was fused either to the N- or the C-terminus of ApcEΔ or inserted between residues 76 and 78, thereby replacing the native hydrophobic loop domain. We describe the assembly, spectral characteristics, and intramolecular excitation energy transfer of two unique systems: in the first, the short-wavelength absorbing zinc-mesoporphyrin is bound to the HP7 domain and serves as an excitation-energy donor to the long-wavelength absorbing phycocyanobilin bound to the ApcE domain; in the second, the short-wavelength absorbing phycoerythrobilin is bound to the ApcE domain and serves as an excitation energy donor to the long-wavelength absorbing zinc-bacteriochlorophyllide bound to the HP7 domain. All the systems that were constructed and tested exhibited significant intramolecular fluorescence resonance energy transfer with yields ranging from 21% to 50%. This confirms that our modular, covalent approach for studying EET between the cyclic and open chain tetrapyrroles is reasonable, and may be extended to larger structures mimicking light-harvesting in cyanobacteria. The design, construction, and characterization process demonstrated many of the advances in constructing such model systems, particularly in our ability to control the fold and aggregation state of protein-based systems. At the same time, it underlines the potential of exploiting the versatility and flexibility of protein-based systems in assembling multiple pigments into effective light-harvesting arrays and tuning the spectral properties of multichromophore systems.

Cyclic voltammetric, fluorescence and biological analysis of purified aeruginosin A, a secreted red pigment of Pseudomonas aeruginosa PAO1

The opportunistic pathogen Pseudomomas aeruginosa produces multiple pigments during in vitro culture and in vivo during colonization of burn wounds and in the airways of cystic fibrosis (CF) patients. One pigment is a deep 'merlot'-coloured compound known as aeruginosin A (AA). However, the red pigment(s) of P. aeruginosa are often collectively called pyorubrin, of which there is no known chemical composition. Here, we purified and confirmed by MS and assessed the physicochemical properties of AA (2-amino-6-carboxy-10-methylphenazinium betaine) by first focusing on its ability to redox-cycle using cyclic voltammetry and its spectroscopic (as well as fluorescent) properties, experiments that were conducted at physiological pH. AA exhibited reversible electrochemistry at a glassy carbon electrode within a potential range of -500 to -200 mV. Electrochemical anodic and cathodic peak currents were observed at -327 and -360 mV, respectively, with a low formal reduction potential of -343.5 mV versus Ag/AgCl. AA absorbed at 516 nm and fluoresced at 606 nm. Results from the spectro-electrochemistry of pyorubrin revealed that its strongest fluorescence was in its parent or oxidized form. Production of AA by P. aeruginosa was found to be controlled by the rhl component of the intercellular signalling system known as quorum sensing and was produced maximally during the stationary growth phase. However, unlike its downstream blue redox-active toxin, pyocyanin, AA had no adverse effects on methicillin-resistant Staphylococcus aureus USA300, Escherichia coli DH5-α or human keratinocytes. We close with some thoughts on the potential commercial use(s) of AA.

Red gall pigmentation: cytokinin stimulation is not everything

Recently, the nature of gall pigmentation phenomenon has gained interest, with different, and often contradicting, explanations and hypotheses. A recent, welcome contribution by Connor et al. (Arthropod–Plant Interact 6:489–495, 2012) suggested that gall pigmentation is a mere “fabricational noise” of the gall development, caused by the production of anthocyanin due to the accumulation of cytokinins and sugars. We propose that this perspective, although probably true in some systems, is an oversimplification of a more complex situation. We argue that since multiple pigments are likely to be involved in gall coloration, and since the link between cytokinins and pigmentation is not obligatory, this is an unlikely general explanation of gall pigmentation. The galling habit has evolved independently among numerous insect lineages and habitats, and therefore, the role of gall pigmentation may vary. It is the time to test the different hypotheses in the field.

Múltiples desprendimientos de epitelio pigmentario idiopático: a propósito de un caso

Case reportA 47 year-old female who presented with a bilateral idiopathic multiple pigment epithelial detachment (PED) in a routine visit. This pathology is shown as a rare clinical manifestation, where the outcome is resolution of localized atrophy of the pigment epithelium, with a good functional prognosis. DiscussionPED is a common clinical manifestation in several chorioretinal diseases, particularly in macular degeneration associated with age. Idiopathic PED can be considered as a kind of central type II serous chorioretinopathy. Fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) are complementary tests to study the number, extension, and nature of these PED.