scholarly journals Evaluation of the effectiveness of cryptic coloration of the Carolina anole’s skin

2019 ◽  
Vol 10 (3) ◽  
pp. 320-326
Author(s):  
A. B. Kiladze

Cryptic coloration of animals’ integument is one of the effective adaptations that allow them to lead an active lifestyle while being protected from natural enemies due to visual disguise. This is achieved by the similarity of body color of a particular individual to the background of various substrates in its environment. The morphological and functional basis of cryptic coloration in vertebrates, including reptiles, is ensured by the skin pigmentation. Using bioinformatic methods, we calculated the skin camouflage index of the Carolina anole (Anolis carolinensis Voigt, 1832) in various conditions of its habitat. The skin camouflage index (Ic) is the ratio of the sum of the average values of rgb coordinates of the skin color to the sum of the average values of rgb coordinates of the color of the external substrate. Ic satisfies the effective level of adaptation to habitat conditions if it falls within the range of 0.80–1.20. It has been shown that rgb-values of the dominant color of the dorsal skin of green anoles slightly differ from the similar parameters characteristic of the deciduous habitat, which is reflected by Ic of its skin (0.94). In the brown anoles on a background of woody substrate, the Ic value of its skin (0.88) is also optimal, since it exceeds the lower limit (0.80), which indicates close values of the sums of the rgb coordinates of the skin color and the color of the external background. In the mixed green-brown anoles, the deciduous habitat is preferable to the woody one. In the first case, Ic (1.11) is in the optimum zone, and in the second case, Ic (0.70) goes beyond the lower limit of the optimum, which indicates a greater vulnerability of the animal to external threats. We have confirmed the relativity of visual hiding of the skin that is effective only in the habitat conditions in which the camouflage abilities of the skin manifest as fully as possible.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingwen Wu ◽  
Zetong Lin ◽  
Genghua Chen ◽  
Qingbin Luo ◽  
Qinghua Nie ◽  
...  

Skin color is an important economic trait in meat-type chickens. A uniform bright skin color can increase the sales value of chicken. Chickens with bright yellow skin are more popular in China, especially in the broiler market of South China. However, the skin color of chickens can vary because of differences in breeds, diet, health, and individual genetics. To obtain greater insight into the genetic factors associated with the process of skin pigmentation in chickens, we used a colorimeter and high-resolution skin photographs to measure and analyze the skin color of chickens. By analyzing 534 chickens of the same breed, age, and feed condition, we found that the yellowness values of the chickens varied within this population. A significant positive correlation was found between the cloacal skin yellowness values before and after slaughter, and the cloacal skin yellowness value of live chickens was positively correlated with the overall body skin yellowness value. Additionally, chicken skin yellowness exhibited low heritability, ranging from 0.07 to 0.27. Through RNA sequencing, 882 genes were found to be differentially expressed between the skin with the highest and lowest yellowness values. Some of these differentially expressed genes may play an important role in yellow pigment deposition in chicken skin, which included TLR2B, IYD, SMOC1, ALDH1A3, CYP11A1, FHL2, TECRL, ACACB, TYR, PMEL, and GPR143. In addition, we found that the expression and variations of the BCO2 gene, which is referred to as the yellow skin gene, cannot be used to estimate the skin yellowness value of chickens in this population. These data will help to further our understanding of chicken skin yellowness and might contribute to the selection of specific chicken strains with consistent skin coloration.



2020 ◽  
Author(s):  
Sagnik Palmal ◽  
Kaustubh Adhikari ◽  
Javier Mendoza-Revilla ◽  
Macarena Fuentes-Guajardo ◽  
Caio C. Silva de Cerqueira ◽  
...  

AbstractWe report an evaluation of prediction accuracy for eye, hair and skin pigmentation based on genomic and phenotypic data for over 6,500 admixed Latin Americans (the CANDELA dataset). We examined the impact on prediction accuracy of three main factors: (i) The methods of prediction, including classical statistical methods and machine learning approaches, (ii) The inclusion of non-genetic predictors, continental genetic ancestry and pigmentation SNPs in the prediction models, and (iii) Compared two sets of pigmentation SNPs: the commonly-used HIrisPlex-S set (developed in Europeans) and novel SNP sets we defined here based on genome-wide association results in the CANDELA sample. We find that Random Forest or regression are globally the best performing methods. Although continental genetic ancestry has substantial power for prediction of pigmentation in Latin Americans, the inclusion of pigmentation SNPs increases prediction accuracy considerably, particularly for skin color. For hair and eye color, HIrisPlex-S has a similar performance to the CANDELA-specific prediction SNP sets. However, for skin pigmentation the performance of HIrisPlex-S is markedly lower than the SNP set defined here, including predictions in an independent dataset of Native American data. These results reflect the relatively high variation in hair and eye color among Europeans for whom HIrisPlex-S was developed, whereas their variation in skin pigmentation is comparatively lower. Furthermore, we show that the dataset used in the training of prediction models strongly impacts on the portability of these models across Europeans and Native Americans.



Author(s):  
Olumayowa Abimbola Oninla ◽  
Samuel Olorunyomi Oninla ◽  
Bolaji Ibiesa Otike-Odibi ◽  
Mufutau Muphy Oripelaye ◽  
Fatai Olatunde Olanrewaju ◽  
...  

Microscopic structures in the skin are basically the same in all races. Differences are found in histology and physiology of the skin resulting in different skin types, needs and prevailing skin diseases. Skin pigmentation (with the photo-protective properties), and the barrier function of the stratum corneum are the main differences between African and Caucasian skin. The geographic distribution of UV radiation (UVR) has a positive correlation with geographical location. The darker-skinned populations are closer to the equator where there are high amounts of UVR especially in the tropical regions of the world. African skin has the greatest variability in skin color. Africa has both white and dark skinned individuals with the darker-skinned populations being mostly around the equator.          Leslie Baumann introduced four parameters that more accurately characterized skin types than previous classification of dry, oily, normal and combination skin. These are dry or oily – D/O; sensitive or resistant – S/R; pigmented or non-pigmented – P/N, and wrinkled or unwrinkled skin – W/T. Combinations of these further produced sixteen skin phenotypes.  Dark skinned individuals often have the PT types while the light skinned mostly have the NW types. Skin needs basically depends on the type. Identifying the skin type is fundamental to providing the right skin care. According to Baumann, the fundamental elements of skin care are mild cleansing, hydrating (moisturization with humectants and emollients), replenishing (with lipids, ceramides and fatty acids) and skin protection (UV protection and increased humidity). Skin diseases are associated with skin type. Eczema is more typical in people with DS combinations while acne is associated with OS skin type (especially OSNT and OSPT). Prevalence of skin diseases varies within African communities from 35% to 87% with skin infections affecting 22-46% and eczemas 13-21% of patients in various studies.





1993 ◽  
Vol 73 (3_part_1) ◽  
pp. 1007-1010
Author(s):  
Wayne Westhoff

Psychosocial data collected from 12 albinos in rural and isolated parts of the Dominican Republic suggest a stigma is associated with the absence of skin color. The general population living in the area has a skin pigmentation of dark brown. The purpose of the investigation was to assess whether there were psychosocial problems for albinos with white skin and hair. Prior studies imply albinism is a negative social characteristic associated with prejudice and apartheid in a predominately mulatto community. This researcher recommends that psychologists and health-care providers be familiar with similar sensitive issues among special populations.



2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Myra O. Villareal ◽  
Sayuri Kume ◽  
Mohamed Neffati ◽  
Hiroko Isoda

Melanin provides inherent protection against skin cancer by absorbing broad-spectrum radiant energy of UV radiation. Cutaneous malignant melanoma incidence has recently been observed to increase and the frequency is closely associated with the skin color, highlighting the importance of skin pigmentation. Here, we showed how melanin biosynthesis is enhanced by treatment with phenolic compounds-richCymbopogon schoenanthus(CYM) in B16 murine melanoma cells and human epidermal melanocytes (HEM). CYM increased the melanin content of the cells by upregulating the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase (DCT) at the protein and mRNA levels, comparable to the effect ofα-melanocyte-stimulating hormone (MSH), in both B16 cells and HEM. Moreover, global gene expression analysis showed that at least 44 pigmentation-associated genes were modulated, including the microphthalmia-associated transcription factor(Mitf)and its transcriptional regulators (Sox10,Pax3, andLef1). Upregulation of copper transport-associated geneAtp7bindicates that CYM also promotes tyrosinase activity. CYM upregulatedMitfand possibly activates tyrosinase enzyme, providing evidence for its possible use to promote melanogenesis and as a therapeutic agent against hypopigmentation disorders.



Author(s):  
Peter M. Sanchez ◽  
David Doherty ◽  
Kirstie Lynn Dobbs

Abstract Is darker skin pigmentation associated with less favorable social and political outcomes in Latin America? We leverage data from 18 Latin American countries across multiple survey waves to demonstrate the robust and potent negative relationship between the darkness of skin tone and socio-economic status. Then we examine the relationship between skin color and attitudes toward the political system. In spite of our substantial sample size, we find little support for the expectation that respondents with darker skin are less favorably disposed toward the political system—indeed, on balance, our findings run counter to this expectation. Our findings suggest that the socio-economic “pigmentocracy” that pervades the region does not necessarily translate into pronounced differences in attitudes about the political system. This finding casts some doubt on the expectation that social inequalities are likely to destabilize governments or undermine their legitimacy.



2019 ◽  
Vol 10 (3) ◽  
pp. 13-16
Author(s):  
Sumit Maitra ◽  
Diptendu Chatterjee ◽  
Arup Ratan Bandyopadhyay

Background: Skin pigmentation is one of the most variable phenotypic traits and most noticeable of human polymorphisms. Skin pigmentation in humans is largely determined by the quantity and distribution of the pigment melanin. The literature review on skin color variation revealed a few works on skin pigmentation variation has been conducted in India from Southern, Western and Northern part. Aims and Objectives: To best of the knowledge, the present discourse is the first attempt to understand skin color variation from Eastern and North Eastern part of India among three populations. Materials and Methods: The present study consisted of 312 participants from Chakma and Tripuri groups of Tripura, North East India, and participants from Bengalee Hindu caste population from West Bengal. Skin color was measured by Konica Minolta CR-10 spectrophotometer which measures and quantifies the colors with a 3D color space (CIELAB) color space created by 3 axes. All the skin color measurements from each participant were taken from unexposed (underarm) left and right to get a mean and exposed (forehead) to sunlight. Results: The distribution of skin color variation among the three populations demonstrated significant (p<0.05) difference in lightness for unexposed and exposed indicating lightness in unexposed area. Furthermore, the present study revealed significant difference (p<0.05) in skin color among the ethnic groups across the body location and all three attributes (lightness, redness and yellowness). Conclusion: Generally, skin color variation may be elucidated by two main factors: individual differences in lightness and yellowness and by and large due to ethnicity, where diversity in redness is due to primarily due to different body locations. Variation in lightness have more characteristic probability. The present study first time reports the wide range of quantitative skin color variation among the three ethnic groups from Eastern and North East India and highest yellowness (b*) among the population from North East India.



2012 ◽  
Vol 2012 ◽  
pp. 1-3
Author(s):  
César Faillace ◽  
Jozélio Freire de Carvalho

Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder characterized by neuropathic pain associated with local edema and changes suggestive of autonomic involvement such as altered sweating, skin color, and skin temperature of the affected region. CRPS was described associated with several diseases, such as trauma, psychiatric conditions, and cancer. However, no case associated with Still's disease has been previously described. In this paper, the authors describe the first case of CRPS associated with Still's disease.



2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 9127-9127 ◽  
Author(s):  
S. E. Lai ◽  
L. Minnelly ◽  
P. O'Keeffe ◽  
A. Rademaker ◽  
J. Patel ◽  
...  

9127 Background: A papulopustular reaction occurs in 68–75% of patients undergoing treatment with the epidermal growth factor receptor (EGFR) inhibitor erlotinib, necessitating dose modification or interruption in 14% and 12% of patients, respectively. Based on preclinical data showing that EGFR inhibition in the skin may potentiate the harmful effects of ultraviolet radiation (UVR) exposure, sun protection is generally advocated. Because the level of melanin, a biological pigment in the epidermis, correlates with increased intrinsic protection against the harmful effects of UVR, we hypothesized that lower levels of skin pigmentation would be associated with higher frequency and severity of erlotinib rash. Methods: We conducted a retrospective chart review of 42 patients undergoing erlotinib therapy to characterize the relationship between skin sensitivity to UVR and severity of EGFR inhibitor rash. Skin sensitivity to UVR was categorized using the Fitzpatrick skin phototype (SPT) classification scheme, and individuals were grouped in phototypes I/II, III/IV, and V/VI. Grading of rash was performed using the NCI-CTC criteria version 2.0 and 3.0. Results: Patients with SPT I/II developed rash grades 0 (6%), 1/2 (31%), and 3/4 (63%), whereas patients with skin phototype III/IV had rash grade 0 (26%), 1/2 (68%), and 3/4 (5%). Patients with SPT V/VI had rash grade 0 (43%), 1/2 (57%), and 3/4 (0%). Lower skin phototypes had higher grade rash (p=0.0006 by Fisher's exact test). Conclusions: Management of cutaneous side effects from EGFR inhibitors is important in order to achieve maximal patient compliance and anti-cancer therapeutic benefit, and the correlation between rash and survival underscores maintaining patients on therapy. The results of this study suggest that SPT may be an independent predictive factor for EGFR inhibitor-induced skin toxicities, thus impacting pre-therapy counseling and early intervention. [Table: see text]



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