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Smoky rubyspot damselflies (Hetaerina titia Drury, 1773) are one of the most commonly encountered odonates along streams and rivers on both slopes of Central America and the Atlantic drainages in the United States and southern Canada. Owing to their highly variable wing pigmentation, they have become a model system for studying sexual selection and interspecific behavioral interference. Here, we sequence and assemble the genome of a female smoky rubyspot. Of the primary assembly (i.e. the principle pseudohaplotype), 98.8% is made up of 12 chromosomal pseudomolecules (2N = 22A + X). There are 75 scaffolds in total, an N50 of 120 Mb, a contig-N50 of 0.64 Mb, and a high arthropod BUSCO score [C: 97.6% (S: 97.3%, D: 0.3%), F: 0.8%, M: 1.6%]. We then compare our assembly to that of the blue-tailed damselfly genome (Ischnura elegans), the most complete damselfly assembly to date, and a recently published assembly for an American rubyspot damselfly (Hetaerina americana). Collectively, these resources make Hetaerina a genome-enabled genus for further studies of the ecological and evolutionary forces shaping biological diversity.

Animal pigment patterns are excellent models to elucidate mechanisms of biological organization. Although theoretical simulations, such as Turing reaction-diffusion systems, recapitulate many animal patterns, they are insufficient to account for those showing a high degree of spatial organization and reproducibility. Here, we study the coat of the African striped mouse (Rhabdomys pumilio) to uncover how periodic stripes form. Combining transcriptomics, mathematical modelling and mouse transgenics, we show that the Wnt modulator Sfrp2 regulates the distribution of hair follicles and establishes an embryonic prepattern that foreshadows pigment stripes. Moreover, by developing in vivo gene editing in striped mice, we find that Sfrp2 knockout is sufficient to alter the stripe pattern. Strikingly, mutants exhibited changes in pigmentation, revealing that Sfrp2 also regulates hair colour. Lastly, through evolutionary analyses, we find that striped mice have evolved lineage-specific changes in regulatory elements surrounding Sfrp2, many of which may be implicated in modulating the expression of this gene. Altogether, our results show that a single factor controls coat pattern formation by acting both as an orienting signalling mechanism and a modulator of pigmentation. More broadly, our work provides insights into how spatial patterns are established in developing embryos and the mechanisms by which phenotypic novelty originates.

Coloration facilitates evolutionary investigations in nature because the interaction between genotype, phenotype and environment is relatively accessible. In a landmark set of studies, Endler addressed this complexity by demonstrating that the evolution of male Trinidadian guppy coloration is shaped by the local balance between selection for mate attractiveness versus crypsis. This became a textbook paradigm for how antagonistic selective pressures may determine evolutionary trajectories in nature. However, recent studies have challenged the generality of this paradigm. Here, we respond to these challenges by reviewing five important yet underappreciated factors that contribute to colour pattern evolution: (i) among-population variation in female preference and correlated variation in male coloration, (ii) differences in how predators versus conspecifics view males, (iii) biased assessment of pigmentary versus structural coloration, (iv) the importance of accounting for multi-species predator communities, and (v) the importance of considering the multivariate genetic architecture and multivariate context of selection and how sexual selection encourages polymorphic divergence. We elaborate these issues using two challenging papers. Our purpose is not to criticize but to point out the potential pitfalls in colour research and to emphasize the depth of consideration necessary for testing evolutionary hypotheses using complex multi-trait phenotypes such as guppy colour patterns.

Background: The ceramic soft tissue trimming bur (CeraTip™) was initially introduced for use in gingivoplasty but has recently been used for gingival depigmentation. The aim of this study is to compare the efficacy of depigmentation between the novel CeraTip™ and the gold-standard surgical scalpel technique. Methods: Eight healthy, nonsmokers with moderate to severe gingival hyperpigmentation in both arches were randomly assigned for CeraTip™ depigmentation in one arch as the test group (TG) and scalpel depigmentation in the opposite arch as the control group (CG). Pigmentation indices were used to assess clinical performance. Treatment time, pain level, and esthetic satisfaction were the parameters of patient experience. The assessments were performed at baseline, one week, one month, and three months. Results: At all assessment visits, pigmentation intensity represented by the Dummet oral pigmentation index (DOPI), and pigmentation distribution represented by the Hedin melanin index (MI), were significantly lower than those at baseline (p < 0.001) in both groups. When comparing the two groups, Scalpel depigmentation had better initial clinical outcomes, while CeraTip™ had less visible repigmentation, pain scores, treatment time, and greater esthetic satisfaction. However, none of the differences were statistically significant. Conclusion: Both techniques successfully removed gingival hyperpigmentation with comparable clinical performance. The patients preferred CeraTip™ depigmentation. Trial registration: The study protocol was registered on 11/09/2023 on the www.clinicaltrials.gov database (NCT06031116) after the approval of the Ethics Committee, Faculty of Dentistry, Ain Shams University (FDASU-Rec012124). [ABSTRACT FROM AUTHOR]

Albinism is a phenotypically and genetically heterogeneous condition characterized by a variable degree of hypopigmentation and by ocular features leading to reduced visual acuity. Whereas numerous genotypic studies have been conducted throughout the world, very little is known about the genotypic spectrum of albinism in Africa and especially in sub‐Saharan Western Africa. Here we report the analysis of all known albinism genes in a series a 23 patients originating from Mali. Four were diagnosed with OCA 1 (oculocutaneous albinism type 1), 17 with OCA 2, and two with OCA 4. OCA2 variant NM_000275.3:c.819_822delinsGGTC was most frequently encountered. Four novel variants were identified (two in TYR, two in OCA2). A deep intronic variant was found to alter splicing of the OCA2 RNA by inclusion of a pseudo exon. Of note, the OCA2 exon 7 deletion commonly found in eastern, central, and southern Africa was absent from this series. African patients with OCA 1 and OCA 4 had only been reported twice and once, respectively, in previous publications. This study constitutes the first report of the genotypic spectrum of albinism in a western sub‐Saharan country. [ABSTRACT FROM AUTHOR]

Epidermal melanin unit integrity is crucial for skin homeostasis and pigmentation. Epidermal growth factor (EGF) receptor (EGFR) is a pivotal player in cell growth, wound healing, and maintaining skin homeostasis. However, its influence on skin pigmentation is relatively unexplored. This study investigates the impact and underlying mechanisms of EGFR inhibitors on skin pigmentation. We evaluated EGF and EGFR expression in various skin cells using quantitative real‐time PCR, Western blot, and immunofluorescence. EGF and EGFR were predominantly expressed in epidermal keratinocytes, and treatment with the EGFR tyrosine kinase inhibitors (EGFR‐TKIs) gefitinib and PD153035 significantly increased stem cell factor (SCF) and endothelin‐1 (ET‐1) expression in cultured keratinocytes. Enhanced melanocyte migration and proliferation were observed in co‐culture, as evidenced by time‐lapse live imaging and single‐cell tracking assays. Furthermore, topical application of gefitinib to guinea pig dorsal skin induced increased pigmentation and demonstrated efficacy in mitigating rhododendrol‐induced leukoderma. Suppression of EGF signaling indirectly enhanced skin pigmentation by upregulating SCF and ET‐1 in epidermal keratinocytes. This novel mechanism highlights the pivotal role of EGF signaling in regulating skin pigmentation, and topical EGFR‐TKI therapy at an appropriate dose may be a promising approach for depigmentation disorder management. [ABSTRACT FROM AUTHOR]

Post‐inflammatory hyperpigmentation (PIH) is a hypermelanosis that often occurs secondary to skin irritation or injury, especially in darker skin tones, for which there is currently a lack of effective treatment options. Few preclinical models are available to study PIH. Here, we show that the Yucatan miniature pig consistently develops PIH after skin injuries. Skin wounds were produced on Yucatan pigs by needle punches, full‐thickness excisions, or burns. Wound sites were monitored and photographed regularly. Tissue samples were collected after 24 weeks and processed for histology/immunohistochemistry. Skin pigmentation and histologic changes were quantified by computer‐assisted image analyses. All injury methods resulted in hyperpigmentation. Melanin content at the histologic level was quantified in the larger (burn and excision) wounds, showing a significant increase compared to uninjured skin. Increased melanin was found for both epidermal and dermal regions. Dermal melanin deposits were primarily clustered around the papillary vasculature, and were associated not with melanocytes but with leukocytes. The Yucatan miniature pig model recapitulates key clinical and histologic features of PIH in humans, including skin hyperpigmentation at both gross and histologic levels, and persistence of dermal melanin subsequent to injury. This model could be used to further our understanding of the etiology of PIH, and for new therapy development. [ABSTRACT FROM AUTHOR]

Background: The COVID‐19 pandemic brought about a new normal, necessitating the use of personal protective equipment (PPE) like face shields, surgical masks, gloves, and goggles. However, prolonged mask‐wearing introduced skin‐related issues due to changes in the skin's microenvironment, including increased humidity and temperature, as well as pressure on the skin. These factors led to skin deformation, vascular issues, edema, and inflammation, resulting in discomfort and cosmetic concerns. Clinical reports quickly highlighted the consequences of long‐term mask use, including increased cases of "maskne" (mask‐related acne) or mask‐wearing related disorders such as rosacea flare‐ups, skin‐barrier defects, itching, erythema, redness, hyperpigmentation, and lichenification. Some of these issues, like inflammation, oxidative stress, and poor wound healing, could be directly linked to acne‐related disorders or skin hypoxia. Aim: To address these problems, researchers turned to rutin, a well‐known flavonoid with antioxidant, vasoactive, and anti‐inflammatory properties. However, rutin's poor water solubility presented a challenge for cosmetic formulations. To overcome this limitation, a highly water‐soluble form of rutin was developed, making it suitable for use at higher concentrations. Methods: In vitro and ex vivo tests were conducted, as well as an innovative clinical trial including volunteers wearing surgical masks for at least 2 h, to evaluate the biological activity of this soluble rutin on the main skin concerns associated with mask‐wearing (inflammation, oxidative stress, skin repair, hyperpigmentation, and skin redness). Results: The in vitro results showed that the active ingredient significantly reduced oxidative stress, improved wound healing, and reduced inflammation. In dark skin explants, the active ingredient significantly reduced melanin content, indicating its lightening activity. This effect was confirmed in the clinical study, where brown spots decreased significantly after 4 days of application. Moreover, measurements on volunteers demonstrated a decrease in skin redness and vascularization after the active ingredient application, indicating inflammation and erythema reduction. Volunteers reported improved skin comfort. Conclusion: In summary, the COVID‐19 pandemic led to various skin issues associated with mask‐wearing. A highly soluble form of rutin was developed, which effectively addressed these concerns by reducing inflammation, oxidative stress, and hyperpigmentation while promoting wound healing. This soluble rutin offers a promising solution for the rapid treatment of maskne‐related disorders and other skin problems caused by prolonged mask use. [ABSTRACT FROM AUTHOR]

Microenvironment and transcriptional plasticity generate subpopulations within the tumor, and the use of BRAF inhibitors (BRAFis) contributes to the rise and selection of resistant clones. We stochastically isolated subpopulations (C1, C2, and C3) from naïve melanoma and found that the clones demonstrated distinct morphology, phenotypic, and functional profiles: C1 was less proliferative, more migratory and invasive, less sensitive to BRAFis, less dependent on OXPHOS, more sensitive to oxidative stress, and less pigmented; C2 was more proliferative, less migratory and invasive, more sensitive to BRAFis, less sensitive to oxidative stress, and more pigmented; and C3 was less proliferative, more migratory and invasive, less sensitive to BRAFis, more dependent on OXPHOS, more sensitive to oxidative stress, and more pigmented. Hydrogen peroxide plays a central role in oxidative stress and cell signaling, and PRDXs are one of its main consumers. The intrinsically resistant C1 and C3 clones had lower MITF, PGC-1α, and PRDX1 expression, while C1 had higher AXL and decreased pigmentation markers, linking PRDX1 to clonal heterogeneity and resistance. PRDX2 is depleted in acquired BRAFi-resistant cells and acts as a redox sensor. Our results illustrate that decreased pigmentation markers are related to therapy resistance and decreased antioxidant defense. [ABSTRACT FROM AUTHOR]

Background: Hyperpigmented scars, particularly in exposed body areas, can be difficult to conceal and may evoke psychological distress. While the precise causes of scar dyschromia are not fully understood, alterations in melanogenic activity appear to hold more significance than changes in melanocyte quantity. Current treatments encompass laser interventions. However, it is essential to consider their costs and potential complications in relation to their limited proven effectiveness. Fat grafting has gained interest as a scar modulation technique due to its regenerative properties, and its efficacy in reducing scar hyperpigmentation is currently under investigation. Methods: A systematic review and meta-analysis was reported according to PRISMA guidelines. PubMed, Embase, and Cochrane Library databases were accessed. PROSPERO registration number is CRD42023457778. The primary outcome was a change in scar pigmentation after fat grafting. Pigmentation changes after fat grafting were calculated using the standardized mean difference (SMD) between baseline and postoperative scores according to POSAS and VSS scales. Bias assessment was conducted according to the National Institute for Health and Clinical Excellence quality assessment tool. Results: A total of 8 articles meeting inclusion and exclusion criteria were identified, involving 323 patients with hyperpigmented scars treated with fat grafting. A significant difference in scar pigmentation was noted after treatment with fat grafting according to observers' ratings, with a SMD of − 1.09 [95% CI: − 1.32; − 0.85], p<0.01. The SMD for patient-reported scar pigmentation after treatment with fat grafting was − 0.99 [96% CI: − 1.31; − 0.66], p<0.01. Four studies provided objective measurements of melanin changes after fat grafting and revealed inconsistent findings compared to subjective observations. Conclusions: Fat grafting shows promise in ameliorating hyperpigmented scars based on subjective assessments, but further corroborating evidence from objective measures is required. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

The yellow gene family plays a crucial role in insect pigmentation. It has potential for use as a visible marker gene in genetic manipulation and transgenic engineering in several model and non‐model insects. Sadly, yellow genes have rarely been identified in Stratiomyidae species and the functions of yellow genes are relatively unknown. In the present study, we first manually annotated and curated 10 yellow genes in the black soldier fly (BSF), Hermetia illucens (Stratiomyidae). Then, the conserved amino acids in the major royal jelly proteins (MRJPs) domain, structural architecture and phylogenetic relationship of yellow genes in BSF were analyzed. We found that the BSF yellow‐y, yellow‐c and yellow‐f genes are expressed at all developmental stages, especially in the prepupal stage. Using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein 9 (Cas9) system, we successfully disrupted yellow‐y, yellow‐c and yellow‐f in the BSF. Consequently, the mutation of yellow‐y clearly resulted in a pale‐yellow body color in prepupae, pupae and adults, instead of the typical black body color of the wild type. However, the mutation of yellow‐c or yellow‐f genes did not result in any change in color of the insects, when compared with the wild type. Our study indicates that the BSF yellow‐y gene plays a role in body pigmentation, providing an optimal marker gene for the genetic manipulation of BSF. [ABSTRACT FROM AUTHOR]

Temperature aff ects the distribution and success of Apis mellifera subspecies. To survive high temperatures in their natural habitats, unique adaptive traits have been evolved by various A. mellifera subspecies. A. mellifera jemenitica is a subtropical subspecies that is native to the Arabian Peninsula. It is one of the most thermotolerant A. mellifera subspecies and the only subspecies that can successfully survive long summers with daily temperatures exceeding 45°C in the Arabian Peninsula. In hot, dry conditions and short seasons, A. m. jemenitica can successfully establish its colonies. In this article, the diff erent morphological, behavioural and physiological aspects of the thermal adaptation of A. m. jemenitica, which are its size, pigmentation, brood cell size, seasonal cycle, foraging behaviour, heat shock proteins and life genes are discussed. These aspects account for how A. m. jemenitica can withstand and survive the high summer temperatures on the Arabian Peninsula. [ABSTRACT FROM AUTHOR]

Background Aims Patients/Methods Results Conclusions Skin photoaging and uneven pigmentation are common dermatological concerns. Tetrahexyldecyl ascorbate (THDA) and acetyl zingerone (AZ) are potent antioxidants that have been shown to have anti‐photoaging and anti‐pigmentation effects. THDA is a more stable and penetrable form of vitamin C. AZ is an antioxidant derived from ginger which has clinical evidence for improving photoaging. However, no studies have assessed how they may synergistically act on the skin.This study aims to assess whether a serum containing both THDA and AZ can improve photoaging and the appearance of uneven facial pigmentation.This open‐label study was conducted on 35 healthy individuals aged 21–55. All subjects were instructed to use three to five drops of the topical serum (Power‐C Serum, Image Skincare, Lantana, FL) daily for 12 weeks. Videomicroscopy and high‐resolution photography and various skin biophysical measurements were taken at baseline, 1, 4, and 12 weeks. Outcomes included skin tone and pigmentation, transepidermal water loss (TEWL), skin smoothness, firmness, and elasticity.Compared to baseline, the results at 12 weeks revealed significant decreases in skin pigmentation (p < 0.0001), decreased fine lines and wrinkles (p < 0.0001), and increased smoothness (p < 0.0001), firmness (p < 0.0001), and elasticity (p < 0.0001). Additionally, transepidermal water loss was significantly decreased at 4 weeks compared to baseline (p = 0.01), indicating an increased epidermal barrier integrity.Overall, these findings provide evidence for the combined use of THDA and AZ to address skin photoaging and dyspigmentation changes. [ABSTRACT FROM AUTHOR]

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that visible light (VL), especially blue light (BL), could cause significant skin damage. With the emergence of VL protection products, a harmonization of light protection methods has been proposed, but it has not been widely applied in the Chinese population. Objective: Based on this framework, we propose an accurate and simplified method to evaluate the efficacy of BL photoprotection for the Chinese population. Methods: All subjects (n = 30) were irradiated daily using a blue LED light for four consecutive days. Each irradiation dose was 3/4 MPPD (minimum persistent pigmentation darkening). The skin pigmentation parameters, including L*, M, and ITA°, were recorded. We proposed the blue light protection factor (BPF) metric based on the skin pigmentation parameters to evaluate the anti-blue light efficacies of different products. Results: We found that the level of pigmentation rose progressively and linearly as blue light exposure increased. We proposed a metric, BPF, to reflect the anti-blue light efficacy of products based on the linear changes in skin pigment characteristics following daily BL exposure. Moreover, we discovered that the BPF metric could clearly distinguish the anti-blue light efficacies between two products and the control group, suggesting that BPF is an efficient and simple-to-use metric for anti-blue light evaluation. Conclusion: Our study proposed an accurate and simplified method with an easy-to-use metric, BPF, to accurately characterize the anti-blue light efficacies of cosmetic products, providing support for further development of anti-blue light cosmetics. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify genes regulated by cyclin dependent kinases 5 (CDK5) that participate in hair pigmentation in mice. Methods: The mRNA expression profiles of skin samples from CDK5-knockdown mice were constructed using high-throughput RNA sequencing and compared with those of wild-type mice. Results: In total, 8,002 known genes were differentially expressed between CDK5-knockdown and wild-type mice. Of these, 3,658 were upregulated and 4,344 were downregulated in the skin of CDK5-knockdown mice. An additional 318 previously unknown genes were also differentially expressed, with 171 downregulated and 147 upregulated genes in the skin of CDK5-knockdown mice. Of the known genes expressed in mouse skin, 80 were associated with hair color, with 61 showing lower expression and 19 exhibiting higher expression in skin of CDK5-knockdown mice. Importantly, the expression of the tyrosinase-related protein 1 (TYRP1) and the calcium signaling pathway were also found to be regulated by CDK5, suggesting that pigmentation is regulated by CDK5 via the calcium signaling pathway and TYRP1. Conclusion: The transcriptome profiles obtained from the skin of CDK5-knockdown mice compared to wild-type mice provide a valuable resource to help understand the mechanism by which CDK5 regulates melanogenesis in mice and other animals. [ABSTRACT FROM AUTHOR]

Vitiligo is a chronic skin disorder characterized by the loss of pigmentation, resulting in white patches on the skin. The condition arises from the destruction of melanocytes, the cells responsible for producing melanin, the pigment that gives colour to the skin, hair, and eyes. Although the exact etiology of vitiligo remains elusive, it is believed to involve a complex interplay of genetic, autoimmune, and environmental factors. This overview provides the key aspects of vitiligo, including its epidemiology, pathogenesis, clinical manifestations, and current treatment approaches. The prevalence of vitiligo varies globally, affecting individuals of all ethnic backgrounds and age groups. The autoimmune hypothesis proposes that the immune system mistakenly targets and attacks melanocytes, leading to their destruction. Triggering factors, such as oxidative stress, viral infections, and neural factors, may contribute to the initiation and progression of vitiligo. Clinically, vitiligo can significantly impact the quality of life for affected individuals, both psychologically and socially. The distribution and extent of involvement vary, and the condition can affect any part of the body. Various treatment modalities are available for vitiligo, ranging from topical corticosteroids and calcineurin inhibitors to phototherapy and surgical interventions. While these approaches may help to re-pigment the skin to some extent, there is no definitive cure, and the outcomes can be unpredictable. Ongoing research is focused on understanding the molecular mechanisms underlying vitiligo and developing targeted therapies to address the root causes of the disease. [ABSTRACT FROM AUTHOR]

Researchers and consumers are highly interested in wild edible fruits around the world. Prunus jenkinsii grows in the wild and produces edible fruits, substantially contributing to the health, food, and livelihood of the people living in the eastern Himalayas, India. Although this species is extremely valuable, research on it is negligible. In this study, we investigated the changes in biochemical and functional properties at four different stages of fruit growth, including the immature, mature, ripe, and over-ripe stages, and determined the best stages for harvesting. Our findings showed that the fruit at the ripe stage had the highest fruit weight (6.57 ± 0.04 g), pulp content (43.33 ± 1.34%), total soluble solids (15.04 ± 1.14 °Brix), carbohydrate content (34.74 ± 0.08 mg glucose/g fw), phenols (552.41 ± 11.63 mg GAE/100 g fw), flavonoids (153.81 ± 3.44 mg QE/100 g fw), anthocyanins (313.03 ± 11.79 mg cyd-3-glu eq./100 g fw), and FRAP value (1374.54 ± 92.47 mM FeSO4 eq./100 g fw). These characteristics and their corresponding values increased from the immature stage to the ripe stage; then, they decreased in the over-ripe stage. The number of fruits, firmness, acidity, and ascorbic acid content decreased after ripening. The a* value of the peel changed abruptly from green colour (a*, − 9.44 ± 0.59) at the immature stage to red at the mature stage (a*, 3.13 ± 1.03), and then, to reddish-purple (a*, 5.36 ± 0.76 and b* value, − 1.82 ± 0.30) at the ripe stage and dark purple at the over-ripe stage. Therefore, the stages of fruit maturity strongly influenced the biochemical and antioxidant properties of the fruits and also indicated the ideal harvesting period for obtaining fruits of optimum quality. [ABSTRACT FROM AUTHOR]