RED HAIR COLOUR AS A GENETICAL CHARACTER

Women with red hair colour, i.e., 1–9% of female Europeans, tend to be the subject of various stereotypes about their sexually liberated behaviour. The aim of the present case-control study was to explore whether a connection between red hair colour and sexual behaviour really exists using data from 110 women (34% redheaded) and 93 men (22% redheaded). Redheadedness in women, but not in men, correlated with various traits related to sexual life, namely with higher sexual desire as measured by Revised Sociosexual Orientation Inventory, with higher sexual activity and more sexual partners of the preferred gender over the past year, earlier initiation of sexual life, and higher sexual submissiveness. Structural equation modelling, however, showed that sexual desire of redheaded women meditated neither their higher sexual activity nor most of the variability of having more sexual partners. These results indicate that the apparently more liberated sexual behaviour in redheaded women could be the consequence of frequent attempts of potential mates to have sex with redheaded women. Other hypotheses, based on different physiology, faster life history strategy, or altered self-perception of red-haired women induced by stereotypes about them, were also tested and discussed.

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Investigating DNA methylation as a potential mediator between pigmentation genes, pigmentary traits and skin cancer

10.1101/2020.04.29.060566 ◽

2020 ◽

Author(s):

Carolina Bonilla ◽

Bernardo Bertoni ◽

Josine L Min ◽

Gibran Hemani ◽

Hannah R Elliott ◽

...

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Skin Cancer ◽

Cell Carcinoma ◽

Whole Blood ◽

Sun Exposure ◽

European Ancestry ◽

Hair Colour ◽

Red Hair ◽

Increased Risk

AbstractBackgroundIncidence rates for melanoma and non-melanoma skin cancer (NMSC), which includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), have been steadily increasing in all populations. Populations of European ancestry exhibit the highest rates and therefore, have been widely studied. Pigmentation characteristics are well-known risk factors for skin cancer, particularly fair skin, red hair, blue eyes and the inability to tan. Polymorphisms in established pigmentation-related genes have been associated with these traits and with an increased risk of malignancy. However, the functional relationship between genetic variation and disease is still unclear, with the exception of red hair colour variants in the melanocortin 1 receptor (MC1R) gene.ObjectivesThe aim of this study was to explore the possibility that non-coding pigmentation SNPs are associated with pigmentary traits and skin cancer via DNA methylation (DNAm).Methods and ResultsUsing a meta-GWAS of whole blood DNAm from 36 European cohorts (N=27,750; the Genetics of DNA Methylation Consortium, GoDMC), we found that 19 out of 27 pigmentation-associated SNPs distributed within 10 genes (ASIP, BNC2, IRF4, HERC2, MC1R, OCA2, SLC24A4, SLC24A5, SLC45A2, TYR) were associated with 391 DNAm sites across 30 genomic regions. We selected 25 DNAm sites for further analysis.We examined the effect of the chosen DNAm sites on pigmentation traits, sun exposure phenotypes, and skin cancer, and on gene expression in whole blood. We found an association of decreased DNAm at cg07402062 with red hair in the Avon Longitudinal Study of Parents and Children (ALSPAC), and a strong positive association of DNAm at this and correlated sites with higher expression of SPIRE2. Additionally, we investigated the association of gene expression in skin with pigmentation traits and skin cancer. The expression of ASIP, FAM83C, NCOA6, CDK10, and EXOC2 was associated with hair colour, whilst that of ASIP and CDK10 also had an effect on melanoma and BCC.ConclusionsOur results indicate that DNAm and expression of genes in the 16q24.3 and 20q11.22 regions, deserve to be further investigated as potential mediators of the relationship between genetic variants, pigmentation/sun exposure phenotypes, and some types of skin cancer.

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Association of five SNPs with human hair colour in the Polish population

10.1101/087429 ◽

2016 ◽

Author(s):

A. Siewierska-Górska ◽

A. Sitek ◽

E. Żądzińska ◽

G. Bartosz ◽

D. Strapagiel

Keyword(s):

Association Analysis ◽

Predictive Accuracy ◽

Statistical Significance ◽

P Value ◽

Good Prediction ◽

Polish Population ◽

Operating Characteristics ◽

Hair Colour ◽

Red Hair ◽

Associative Analysis

AbstractTwenty-two variants of the genes involved in hair pigmentation (OCA2, HERC2, MC1R, SLC24A5, SLC45A2, TPCN2, TYR, TYRP1) were genotyped in a group of 186 Polish subjects, representing a range of hair colours (45 red, 64 blond, 77 dark). A genotype-phenotype association analysis was performed.Using z-statistics and the associated p-value, we identified three variants highly associated with different hair colour categories (rs12913832:A>G in HERC2, rs1805007:T>C and rs1805008:C>T in MC1R). Two variants: rs1800401:C>T in OCA2 and rs16891982:C>G in SLC45A2 showed a high probability of a relation with hair colour, although that probability did not exceed the threshold of statistical significance after applying the Bonferroni correction. We created and validated mathematical logistic regression models in order to test the usefulness of the sets of polymorphisms for hair colour prediction in the Polish population. We subjected four models to stratified cross-validation. The first model consisted of three polymorphisms that proved to be important in the associative analysis. The second model included, apart from the mentioned polymorphisms, additionally rs16891982:C>G in SLC45A. The third model included, apart from the variants relevant in the associative analysis, rs1800401:C>T in OCA. The fourth model consisted of the set of polymorphisms from the first model supplemented with rs16891982:C>G in SLC45A and rs1800401:C>T in OCA. The validation of our models showed that the inclusion of rs16891982:C>G in SLC45A and rs1800401:C>T in OCA increases the prediction of red hair in comparison with the algorithm only including rs12913832:A>G in HERC2, rs1805007:T>C and rs1805008:C>T in MC1R. The model consisting of all the five above-mentioned genetic variants showed good prediction accuracies, expressed by the area under the curve (AUC) of the receiver operating characteristics: 0.84 for the red-haired, 0.82 for the dark-haired and 0.71 for the blond-haired. A genotype-phenotype association analysis brought results similar to those in other studies and confirmed the role of rs16891982:C>G, rs12913832:A>G, rs1805007:T>C and rs1805008:C>T in hair colour determination in the Polish population. Our study demonstrated for the first time the possibility of a share of the rs1800401:C>T SNP in the OCA2 gene in hair colour determination. Including this SNP in the actual hair colour predicting models would improve their predictive accuracy.

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Tyrosine supplementation and hair coat pigmentation in puppies with black coats – A pilot study

Journal of Applied Animal Nutrition ◽

10.1017/jan.2015.8 ◽

2015 ◽

Vol 3 ◽

Cited By ~ 3

Author(s):

Adrian Watson ◽

Eric Servet ◽

Marta Hervera ◽

Vincent C. Biourge

Keyword(s):

Coat Colour ◽

Plasma Amino Acids ◽

Hair Colour ◽

Hair Coat ◽

Red Hair ◽

Hair Samples ◽

Cie Lab ◽

Labrador Retrievers ◽

Negative Linear Relationship ◽

Made In

SummaryThe appearance of a red hue to the hair in black coated cats and dogs has previously been reported as a “red hair syndrome”. Such changes in hair colour are related to an alteration in the proportions of two types of pigments produced by melanocytes; black eumelanin and brown pheomelanin. In black cats, it has been demonstrated that higher levels of phenylalanine + tyrosine (Phe+Tyr) than those recommended for growth are required to support eumelanin synthesis. The purpose of this study was to evaluate if a similar observation could be made in dogs. Twelve black coated puppies (Black Labrador retrievers and Newfoundlands) were divided into 3 groups of 4 and fed 3 diets with increasing concentrations of Phe+Tyr (A: 4 g/Mcal; B: 5.8 g/Mcal; C: 7 g/Mcal) for a period of 6 months. Quantification of plasma amino acids (Phe, Tyr, Cys) and spectrocolourimetry of hair samples from the Labrador retrievers (as the a* dimension of CIE Lab system) were performed at the beginning, during and at the end of the study. There was a significant negative linear relationship between plasma Tyr levels and a* values of hair in Labrador dogs on diets A and B, suggesting that a diet with total Phe+Tyr content of 6 g/Mcal (higher than the growth recommended allowance) was necessary to ensure an optimal black coat colour in these puppies and that levels up to 7 g/Mcal can lead to a more intense black coat colour. Moreover, similar to what was found in kittens, plasma levels of Tyr up to 54 μmol/l did not guarantee an optimal black colour coat and led to the “reddish hair” appearance in black coated puppies.

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The genetic architecture of hair colour in the UK population

10.1101/320267 ◽

2018 ◽

Author(s):

Michael D. Morgan ◽

Erola Pairo-Castineira ◽

Konrad Rawlik ◽

Oriol Canela-Xandri ◽

Jonathan Rees ◽

...

Keyword(s):

Hair Growth ◽

Genetic Architecture ◽

Inverse Agonist ◽

Hair Colour ◽

Red Hair ◽

Genes Encoding ◽

The Uk ◽

Variable Penetrance

AbstractWe have extensively mapped the genes responsible for hair colour in the UK population. MC1R mutations are well established as the principal genetic cause of red hair colour, but with variable penetrance. We find variation at genes encoding its agonist (POMC), inverse agonist (ASIP) and other loci contribute to red hair and demonstrate epistasis between MC1R and some of these loci. Blonde hair is associated with over 200 loci, and we find a genetic continuum from black through dark and light brown to blonde. Many of the associated genes are involved in hair growth or texture, emphasising the cellular connections between keratinocytes and melanocytes in the determination of hair colour.

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RED HAIR IN AFRICAN NEGROES: A PRELIMINARY STUDY

Annals of Eugenics ◽

10.1111/j.1469-1809.1953.tb02547.x ◽

1953 ◽

Vol 18 (1) ◽

pp. 211-232 ◽

Cited By ~ 6

Author(s):

N. A. BARNICOT

Keyword(s):

Red Hair ◽

Preliminary Study

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A cyanine-type homolog of the red hair bibenzothiazine chromophore combining reversible proton-sensing with a hydrophobic-to-hydrophilic switching response

Dyes and Pigments ◽

10.1016/j.dyepig.2021.109872 ◽

2021 ◽

pp. 109872

Author(s):

Maria Laura Alfieri ◽

Lucia Panzella ◽

Orlando Crescenzi ◽

Marco d’Ischia ◽

Alessandra Napolitano

Keyword(s):

Red Hair

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Dermatofluoroscopy Is Also for Redheads a Sensitive Method of Early Melanoma Detection

Dermatology ◽

10.1159/000507614 ◽

2020 ◽

Vol 236 (6) ◽

pp. 508-516

Author(s):

Dieter Leupold ◽

Lukasz Szyc ◽

Goran Stankovic ◽

Maja Hofmann ◽

Matthias Scholz ◽

...

Keyword(s):

Fluorescence Spectra ◽

Spectral Characteristics ◽

Spatially Resolved ◽

Melanoma Detection ◽

Dysplastic Nevi ◽

Red Hair ◽

Pigmented Lesions ◽

Melanoma Diagnosis ◽

Increased Risk ◽

Hair Samples

Background: Caucasians with red hair and fair skin have a remarkably increased risk of malignant melanoma compared to non-redhead Caucasians. Objectives: With the aim of a reliable melanoma diagnosis in redheads, the application of dermatofluoroscopy was analyzed in 16 patients with red hair. Most of them had been included in a clinical dermatofluoroscopy study for patients with the suspicion of melanoma. We examined whether the 25 lesions of the redheads showed the same characteristic melanin fluorescence spectra for dysplastic nevi and melanomas as those of non-redhead Caucasians or whether there was a different fluorescence pattern. This is important in view of the known significantly altered ratio of eumelanin to pheomelanin in the skin of redheads. Methods: More than 8,000 spatially resolved fluorescence spectra of 25 pigmented lesions were measured and analysed. The spectra were excited by the stepwise absorption of two 800-nm photons (principle of dermatofluoroscopy). Furthermore, the fluorescence spectra of eumelanin and pheomelanin in hair samples were determined in the same way. Results: The evaluation revealed that the melanin fluorescence spectra of dysplastic nevi and melanomas of redheads have the same spectral characteristics as those of non-redhead Caucasians. An accompanying result is that dermatofluoroscopy shows identical fluorescence spectra for eumelanin and pheomelanin. Conclusions: Dermatofluoroscopy proves to be a reliable diagnostic method also for redheads. Our results also explain our recent finding that there is a uniform fluorescence spectroscopic fingerprint for melanomas of all subtypes, which is of particular interest for hypomelanotic and apparently amelanotic melanomas containing pheomelanin.

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