Brown Eye Color Research Articles

ANALYSIS OF MORPHOLOGICAL TRAITS IN BALOCHI SHEEP BREED OF BALOCHISTAN

Balochi sheep is a popular breed of Balochistan used for meat and fleece production. This breed faces an elevated susceptibility to the annihilation of its distinctive traits due to uncontrolled and indiscriminate breeding practices. The process of phenotypic classification plays a crucial role in facilitating the sustainable utilization, conservation, and enhancement of a particular breed. The current study was conducted to evaluate the morphological attributes for conservation, rearing and breed improvement of the Balochi sheep in Balochistan. Five districts were selected for data collection included Quetta, Sibi, Mastung, Kalat, and Khuzdar. Five flocks were selected from each district, consisting of more than 250 animals. Most of the sheep population had a semi-pendulous ear direction (89.5%). In terms of ear colour, 73.5% of the sheep displayed a white tendency, while 26.5% had black. In male Balochi sheep, several typical morphological characteristics were observed, included wool fiber diameter averaging 37.47±0.06µm, body weight at 39.76±0.87 kg, height 35.20±0.13 inches, chest size of 50.16±0.74 cm, belly circumference of 55.48±0.62 cm, neck length at 7.84±0.46 cm, neck girth of 17.89±0.07 cm, testicle length 8.94±0.43 cm, and testicle diameter of 4.014±0.14 cm. Similarly, in female average values for wool fiber diameter were 37.47±0.06 µm, body weight was 34.02±0.27 kg, height 34.03±0.11 inches, chest size was 47.27±0.49 cm, belly circumference was 51.36±0.49 cm, neck length was 7.84±0.22 cm, neck girth was 17.89±0.03 cm, udder height was 7.86±0.20 cm, udder circumference was 11.83±0.3 cm, teat length was 2.99±0.00 cm, and teat diameter was 1.03±0.01 cm. The coat colour patterns of the overall phenotypes exhibited a mainly uneven distribution, with white coat colour patterns being most prevalent (95%), followed by black and brown patches. The facial head colour exhibited a predominant white pigmentation (85%) with the remaining 15% displaying a partly black shade. The distribution of nose shape among the sheep was 62% minor roman and 38% medium roman. Whereas 89.5% of sheep had an almond-shaped eye structure accompanied by black eyelashes, the remaining 10.5% displayed a brown eye colour. Our study found that 89.5% of Balochi sheep had semi-pendulous ears, 7% had pendulous ears, and 3.5% had ears that were erected upward. Moreover, coat color commonly observed predominantly white, often displaying a combination of white with black and brown patches, which was observed in around 90% of the sheep. Notably, male had horns with curved 56% and 44% straight, while females were hornless. Additionally, 86% of the sheep had legs that were predominantly white with black spots, and the neck color was mostly white, recorded in 90.5%, although some animals showed black spots on their necks. Finally, the belly color was mainly white in 90% animals, with 10% displaying black or brown spots on their bellies. The findings of the present study can be used to improve the management practices for the production and conservation of Balochi sheep breed.

APPLICATION OF MULTIVARIATE STATISTICAL ANALYSIS IN CHARACTERISING THE PHENOTYPIC VARIABILITY OF LOCALLY ADAPTED MUSCOVY DUCKS (CAIRINA MOSCHATA) IN NIGERIA

While there are studies that describe the biometric traits and phenotypic variations in Muscovy ducks in Nigeria, there are limited studies that employ a multivariate approach to depict the phenotypic variability of Muscovy ducks in Nigeria. Therefore, this study aimed to explicate genetic variabilities within C. moschata using qualitative and biometric traits. This study used a multivariate statistical method to phenotypically characterise locally adapted Muscovy duck populations from seven ecogeographical locations in Ibadan, Nigeria. Four qualitative traits (eye colour, bill colour, bean colour and shank colour) and eleven biometric traits (head length, neck length, body length, wings length, shank length, toe length, thigh length, bill length, breast length, breast width and bodyweight) were evaluated in 201 ducks (109 males and 92 females). To study the possible effects of geographical locations on selected phenotypes, frequency distribution, univariate analysis, stepwise and canonical discriminant analyses and cluster analysis were performed. The association between body weight (BWT) and other biometric traits was assessed using the Pearson product-moment correlation coefficient. Male ducks (drakes) were generally more abundant than female ducks (hens). The most prevalent colour traits of locally adapted Muscovy ducks were brown eye colour (70.65 %), black bean colour (62.69 %), pinkish white bill colour (45.27 %) and grey shank colour (56.22 %). Overall, ecogeographical location did not significantly affect (p < 0.05) the measured biometric traits. However, across all locations, the sexual dimorphism was favourable in male ducks, with respect to biometric traits. Stepwise-canonical discriminant analysis revealed a substantial intermixing of biometric traits, especially in Molete, Oje, Adogba and Ajibode ducks. Similarly, the cluster analysis, although it separated the birds into different clusters, showed some level of admixture. The small Mahalanobis distance (0.61 − 3.88) suggested that, with respect to location, there was more morphological similarity than dissimilarity between ducks. The correlation analysis revealed that the body weight of ducks can be fairly estimated from other biometric traits due to their positive, statistically significant correlation. In general, the ducks from all seven ecogeographical locations were rather homogeneous than heterogeneous.

Phenotypic Classification of Eye Colour and Developmental Validation of the Irisplex System on Population Living in Malakand Division, Pakistan.

Eye colour digital photographs and buccal swab samples of 893 individuals of different age groups were collected. Multiplexed SNaPshot single base extension chemistry was used, and the genotypic results were analysed. Snapshot data were used for eye colour prediction through the IrisPlex and FROG-kb tool. The results of the present study found brown eye colour to be the most prevalent eye colour in comparison to intermediate and blue coloured. Overall, individuals with brown-coloured eyes possess CT (46.84%) and TT (53.16%) genotypes. Blue eye-coloured individuals are solely of the CC genotype, while individuals of intermediate eye colour carry CT (45.15%) and CC (53.85%) genotypes in rs12913832 SNP in the HERC2 gene. It was also revealed that brown-coloured eyes individuals were dominant among all age groups followed by intermediate and blue. Statistical analysis between particular variables and eye colour showed a significant p-value (<0.05) for rs16891982 SNP in SLC45A2 gene, rs12913832 SNP in HERC2 gene, rs1393350 SNP in SLC45A2, districts and gender. The rest of the SNPs were non-significant with eye colour, respectively. The rs12896399 SNP and SNP rs1800407 were found significant with rs16891982 SNP. The result also demonstrated that the study group differs from the world population based on eye colour. The two eye colour prediction results were compared, and it was discovered that IrisPlex and FROG-Kb had similar higher prediction ratios for Brown and Blue eye colour. The results of the current study revealed brown eye colour to be the most prevalent amongst members of the local population of Pakhtoon ethnicity in the Malakand Division of northern Pakistan. A set of contemporary human DNA samples with known phenotypes are used in this research to evaluate the custom panel's prediction accuracy. With the aid of this forensic test, DNA typing can be supplemented with details about the appearance of the person from whom the sample was taken in cases involving missing persons, ancient human remains, and trace samples. This study may be helpful for future population genetics and forensics studies.

Association between Variants in the OCA2-HERC2 Region and Blue Eye Colour in HERC2 rs12913832 AA and AG Individuals

The OCA2-HERC2 region is strongly associated with human pigmentation, especially eye colour. The HERC2 SNP rs12913832 is currently the best-known predictor for blue and brown eye colour. However, in a previous study we found that 43 of 166 Norwegians with the brown eye colour genotype rs12913832:AA or AG, did not have the expected brown eye colour. In this study, we carried out massively parallel sequencing of a ~500 kbp HERC2-OCA2 region in 94 rs12913832:AA and AG Norwegians (43 blue-eyed and 51 brown-eyed) to search for novel blue eye colour variants. The new candidate variants were subsequently typed in a Norwegian biobank population (total n = 519) for population specific association analysis. We identified five new variants, rs74409036:A, rs78544415:T, rs72714116:T, rs191109490:C and rs551217952:C, to be the most promising candidates for explaining blue eye colour in individuals with the rs12913832:AA and AG genotype. Additionally, we confirmed the association of the missense variants rs74653330:T and rs121918166:T with blue eye colour, and observed lighter skin colour in rs74653330:T individuals. In total, 37 (86%) of the 43 blue-eyed rs12913832:AA and AG Norwegians could potentially be explained by these seven variants, and we suggest including them in future prediction models.

Evaluation of the IrisPlex system for eye colour prediction in the Serbian population

DNA-based prediction of a physical appearance, also known as DNA phenotyping, is a rapidly developing field with great potential for solving difficult forensic investigations. Externally visible characteristics (EVCs), such as eye colour, are easily recognised and genetically determined. Analysis of highly informative single nucleotide polymorphisms (SNPs) encompassing trait-associated genes provides information about the phenotype of an unknown individual, which is critical in cases where the standard STR profile is not useful. The IrisPlex assay was developed based on genotype data from 3804 Dutch Europeans, with the goal of accurately predicting brown, blue, and undefined eye colours using the six SNP markers alone. This assay has been validated in several studies and has shown high accuracy of prediction for brown and blue eye colours in most European populations. The aim of this work was to evaluate IrisPlex in the Serbian population and to determine if there are possible discrepancies in prediction accuracy compared to the previously published European data. Therefore, we performed the IrisPlex analysis on 65 Serbian individuals. Our results showed that the prediction of eye colour was accurate for about 57% of the respondents, which did not change significantly by applying the 0.7 threshold. The IrisPlex system performed well in predicting blue and brown eye colour in the Serbian sample, achieving high sensitivity levels. However, this model appeared to be unsuitable in the prediction of undefined eye colour, which was a common phenotype in our sample. This low sensitivity suggests a diverse and possibly population-specific genetic background of undefined eye colour. Given the large genetic diversity of the Serbian population, further work on a larger Serbian sample with more SNPs analysed is needed to reveal genetic variants mainly associated with this trait.

Functional Genomics and Eye Color Prediction

The ability to reconstruct a recognizable face from skeletal remains is a useful investigative tool for human identification. Functional genomics plays a role in facial reconstruction through the identification of the regulation of pigmentation pathways. Functional genomics here refers to the study of how genes and intergenic sequences contribute to metabolic pathways and work together to produce a particular phenotype. This form of genetic information adds and confirms the physical traits that help with a visual identification of a person by allowing for the biological predictions of pigmentation for eye, hair, and skin color in facial reconstruction. The principle of SNP testing for eye color prediction from human tooth DNA using both destructive and nondestructive DNA extraction methods is presented using the IrisPlex eye color prediction software. This IrisPlex eye color prediction software is not one hundred percent accurate, and we have explored the classification issues behind those discrepancies by examining DNA from blue, brown, and intermediate eye color donors as well as those donors exhibiting heterochromia (mixed eye colors). The importance of correct prediction of eye color for facial reconstruction is to aid in correct identification of skeletal remains through forensic phenotyping investigation. Irisplex is useful for the correct prediction of blue and brown eye individuals but is less able to distinguish between the subcategories of grey, green, heterochromia and hazel for the intermediate category.

Experimental long-distance haplotyping of OCA2-HERC2 variants

The regulatory HERC2 SNP, rs12913832, is strongly associated with blue and brown eye colour. However, eye colour in heterozygous rs12913832 individuals is observed to vary greatly. Missense mutations in OCA2, such as rs1800407 and rs74653330, are associated with lighter eye colour in some but not all heterozygous rs12913832 individuals. Determining the physical linkage of these variants might help to further explain eye colour variation. So far, experimental haplotyping of these variants has been challenging because the genomic distance between them (∼ 135 kb) exceeds the fragment lengths produced by commonly used DNA isolation kits. The aim for this study was to explore novel methods for long distance haplotyping to assess associations between OCA2-HERC2 haplotypes and eye colour. DNA was isolated from frozen blood samples collected from Norwegians that are known to be heterozygous for both HERC2 rs12913832 and OCA2 SNPs, either rs1800407 (n = 23) or rs74653330 (n = 17), using the newly commercially available Monarch® HMW (heigh molecular weight) DNA Extraction Kit (New England BioLabsinc). We successfully isolated DNA fragments up to 210 kb, which were long enough to haplotype OCA2-HERC2 loci by droplet digital PCR (ddPCR). Three haplotypes were observed in the study population: rs12913832:A-rs1800407:T in 22/23 individuals, rs12913832:A-rs1800407:C in 1/23 individuals and rs12913832:A-rs74653330:T in 16/16 individuals. As expected, all individuals with the rs12913832:A-rs74653330:T haplotype had intermediate to blue eye colour. However, the rs12913832:A-rs1800407:T haplotype was observed in both blue and brown-eyed individuals, suggesting more research is needed.

Association between copy number variations in the OCA2-HERC2 locus and human eye colour

Human eye colour variation is strongly associated with single nucleotide polymorphisms (SNPs) in the OCA2-HERC2 locus, especially rs12913832 that is found in an enhancer element of OCA2. In a previous study we found that 43 out of 166 individuals in a Norwegian population with the brown eye colour genotype HERC2 rs12913832:AA or AG, did not have the expected brown eye colour. To investigate if duplications or deletions in the OCA2-HERC2 locus could explain the blue eye colour in these individuals, we analysed massively parallel sequencing (MPS) data for copy number variations (CNVs) in the OCA2-HERC2 region. The ∼500 kb long OCA2-HERC2 locus was sequenced in 94 individuals with the rs12913832:AG and AA genotypes. Of these, 43 were observed to have blue eye colour and 51 were observed to have brown eye colour. CNVs were analysed using R and the R-package panelcn.MOPS - CNV detection tool for targeted NGS panel data. In rs12913832:AG individuals, CNVs in 32 regions were significantly associated with blue eye colour (Benjamini-Hochberg adjusted p-value ≤ 0.05). In rs12913832:AA individuals, CNVs in 14 regions were associated with blue eye colour using raw p-values (p ≤ 0.05). The functional effects of these CNVs on OCA2 expression are yet to be investigated. However, this study suggests that CNVs in the OCA2-HERC2 locus might explain why some of the rs12913832:AG and AA individuals have unexpectedly blue eyes.

A new approach to broaden the range of eye colour identifiable by IrisPlex in DNA phenotyping

IrisPlex system represents the most popular model for eye colour prediction. Based on six polymorphisms this model provides very accurate predictions that strongly depend on the definition of eye colour phenotypes. The aim of the present study was to introduce a new approach to improve eye colour prediction using the well-validated IrisPlex system. A sample of 238 individuals from a Southern Italian population was collected and for each of them a high-resolution image of eye was obtained. By quantifying eye colour variation into CIELAB space several clustering algorithms were applied for eye colour classification. Predictions with the IrisPlex model were obtained using eye colour categories defined by both visual inspection and clustering algorithms. IrisPlex system predicted blue and brown eye colour with high accuracy while it was inefficient in the prediction of intermediate eye colour. Clustering-based eye colour resulted in a significantly increased accuracy of the model especially for brown eyes. Our results confirm the validity of the IrisPlex system for forensic purposes. Although the quantitative approach here proposed for eye colour definition slightly improves its prediction accuracy, further research is still required to improve the model particularly for the intermediate eye colour prediction.

Multivariate characterisation of morpho-biometric traits of indigenous helmeted Guinea fowl (Numida meleagris) in Nigeria.

This study was conducted to characterise phenotypically helmeted Guinea fowls in three agro-ecologies in Nigeria using multivariate approach. Eighteen biometric characters, four morphological indices and eleven qualitative physical traits were investigated in a total of 569 adult birds (158 males and 411 females). Descriptive statistics, non-parametric Kruskal-Wallis H test followed by the Mann-Whitney U and Dunn-Bonferroni tests for post hoc, Multiple Correspondence Analysis (MCA), Univariate Analysis, Canonical Discriminant Analysis, Categorical Principal Component Analysis and Decision Trees were employed to discern the effects of agro-ecological zone and sex on the morphostructural parameters. Agro-ecology had significant effect (P<0.05; P<0.01) on all the colour traits. In general, the most frequently observed colour phenotype of Guinea fowl had pearl plumage colour (54.0%), pale red skin colour (94.2%), black shank colour (68.7%), brown eye colour (49.7%), white earlobe colour (54.8%) and brown helmet colour (72.6%). The frequencies of helmet shape and wattle size were significantly influenced (P<0.01) by agro-ecology and sex. Overall, birds from the Southern Guinea Savanna zone had significantly higher values (P<0.05) for most biometric traits compared to their Sudano-Sahelian and Tropical Rainforest counterparts. They were also more compact (120.00 vs. 110.00 vs. 107.69) but had lesser condition index (7.66 vs. 9.45 vs. 9.30) and lower long-leggedness (19.71 vs. 19.23 vs. 9.51) than their counterparts from the two other zones. Sexual dimorphism (P<0.05) was in favour of male birds especially those in Southern Guinea Savanna and Sudano-Sahelian zones. However, the MCA and discriminant analysis revealed considerable intermingling of the qualitative physical traits, biometric traits and body indices especially between the Sudano-Sahelian and Tropical Rainforest birds. In spite of the high level of genetic admixture, the Guinea fowl populations could to a relative extent be distinguished using wing length, body length and eye colour. Generally, the birds from the three zones appeared to be more homogeneous than heterogeneous in nature. However, further complementary work on genomics will guide future selection and breeding programs geared towards improving the productivity, survival and environmental adaptation of indigenous helmeted Guinea fowls in the tropics.

Predicting eye and hair colour in a Norwegian population using Verogen’s ForenSeq™ DNA signature prep kit

Prediction of eye and hair colour from DNA can be an important investigative tool in forensic cases if conventional DNA profiling fails to match DNA from any known suspects or cannot obtain a hit in a DNA database. The HIrisPlex model for simultaneous eye and hair colour predictions was developed for forensic usage. To genotype a DNA sample, massively parallel sequencing (MPS) has brought new possibilities to the analysis of forensic DNA samples. As part of an in-house validation, this study presents the genotyping and predictive performance of the HIrisPlex SNPs in a Norwegian study population, using Verogen’s ForenSeq™ DNA Signature Prep Kit on the MiSeq FGx system and the HIrisPlex webtool. DNA-profiles were successfully typed with DNA input down to 125 pg. In samples with DNA input < 125 pg, false homozygotes were observed with as many as 92 reads. Prediction accuracies in terms of AUC were high for red (0.97) and black (0.93) hair colours, as well as blue (0.85) and brown (0.94) eye colours. The AUCs for blond (0.72) and brown (0.70) hair colour were considerably lower. None of the individuals was predicted to have intermediate eye colour. Therefore, the error rates of the overall eye colour predictions were 37% with no predictive probability threshold (pmax) and 26% with a probability threshold of 0.7. We also observed that more than half of the incorrect predictions were for individuals carrying the rs12913832 GG genotype. For hair colour, 65% of the individuals were correctly predicted when using the highest probability category approach. The main error was observed for individuals with brown hair colour that were predicted to have blond hair. Utilising the prediction guide approach increased the correct predictions to 75%. Assessment of phenotype-genotype associations of eye colours using a quantitative eye colour score (PIE-score), revealed that rs12913832 AA individuals of Norwegian descent had statistically significantly higher PIE-score (less brown eye colour) than individuals of non-northern European descent. To our knowledge, this has not been reported in other studies. Our study suggests that careful assessment of the target population prior to the implementation of forensic DNA phenotyping to case work is beneficial.

Prediction of eye and hair pigmentation phenotypes using the HIrisPlex system in a Brazilian admixed population sample.

Human pigmentation is a complex trait, probably involving more than 100 genes. Predicting phenotypes using SNPs present in those genes is important for forensic purpose. For this, the HIrisPlex tool was developed for eye and hair color prediction, with both models achieving high accuracy among Europeans. Its evaluation in admixed populations is important, since they present a higher frequency of intermediate phenotypes, and HIrisPlex has demonstrated limitations in such predictions; therefore, the performance of this tool may be impaired in such populations. Here, we evaluate the set of 24 markers from the HIrisPlex system in 328 individuals from Ribeirão Preto (SP) region, predicting eye and hair color and comparing the predictions with their real phenotypes. We used the HaloPlex Target Enrichment System and MiSeq Personal Sequencer platform for massively parallel sequencing. The prediction of eye and hair color was accomplished by the HIrisPlex online tool, using the default prediction settings. Ancestry was estimated using the SNPforID 34-plex to observe if and how an individual's ancestry background would affect predictions in this admixed sample. Our sample presented major European ancestry (70.5%), followed by African (21.1%) and Native American/East Asian (8.4%). HIrisPlex presented an overall sensitivity of 0.691 for hair color prediction, with sensitivities ranging from 0.547 to 0.782. The lowest sensitivity was observed for individuals with black hair, who present a reduced European contribution (48.4%). For eye color prediction, the overall sensitivity was 0.741, with sensitivities higher than 0.85 for blue and brown eyes, although it failed in predicting intermediate eye color. Such struggle in predicting this phenotype category is in accordance with what has been seen in previous studies involving HIrisPlex. Individuals with brown eye color are more admixed, with European ancestry decreasing to 62.6%; notwithstanding that, sensitivity for brown eyes was almost 100%. Overall sensitivity increases to 0.791 when a 0.7 threshold is set, though 12.5% of the individuals become undefined. When combining eye and hair prediction, hit rates between 51.3 and 68.9% were achieved. Despite the difficulties with intermediate phenotypes, we have shown that HIrisPlex results can be very helpful when interpreted with caution.

Prognostic capacity of the HIrisPlex genetic phenotyping system in the Belarusian population

BACKGROUND: Externally visible traits such as iris and hair color are of interest in different areas of research from archeology and population genetics to forensic science. Recently a number of models have been developed to predict variants of human phenotypic traits. The most popular of them is the HIrisPlex system consisting of 24 SNPs, associated with human eyes and hair color.&#x0D; MATERIALS AND METHODS: We used the HIrisPlex system for phenotyping of the Belarusian population. Allelic variants of the SNPs were genotyped by massive parallel sequencing. The analysis of the obtained data was performed using the free-available online resource https://HIrisPlex.erasmusmc.nl.&#x0D; RESULTS: The comparison of the results of genotyping with actual data showed high accuracy of the system for predicting blue and brown eye color (94.5% and 91.8% of correct predictions, respectively), and in identifying brown-haired (84.7%) and red-haired individuals (80%). The HIrisPlex system successfully predicts iris and hair color in two most numerous phenotypic groups brown-haired with blue eyes (BA = 78.5%) and brown-haired with brown eyes (BA = 85.5%).&#x0D; CONCLUSION: The HIrisPlex system has a high prognostic ability for forensic DNA phenotyping in the Belarusian population. But for traits that are difficult identified, additional researchers are required.

Association between brown eye colour in rs12913832:GG individuals and SNPs in TYR, TYRP1, and SLC24A4

The genotype of a single SNP, rs12913832, is the primary predictor of blue and brown eye colours. The genotypes rs12913832:AA and rs12913832:GA are most often observed in individuals with brown eye colours, whereas rs12913832:GG is most often observed in individuals with blue eye colours. However, approximately 3% of Europeans with the rs12913832:GG genotype have brown eye colours. The purpose of the study presented here was to identify variants that explain brown eye colour formation in individuals with the rs12913832:GG genotype. Genes and regulatory regions surrounding SLC24A4, TYRP1, SLC24A5, IRF4, TYR, and SLC45A2, as well as the upstream region of OCA2 within the HERC2 gene were sequenced in a study comprising 40 individuals with the rs12913832:GG genotype. Of these, 24 individuals were considered to have blue eye colours and 16 individuals were considered to have brown eye colours. We identified 211 variants within the SLC24A4, TYRP1, IRF4, and TYR target regions associated with eye colour. Based on in silico analyses of predicted variant effects we recognized four variants, TYRP1 rs35866166:C, TYRP1 rs62538956:C, SLC24A4 rs1289469:C, and TYR rs1126809:G, to be the most promising candidates for explanation of brown eye colour in individuals with the rs12913832:GG genotype. Of the 16 individuals with brown eye colours, 14 individuals had four alleles, whereas the alleles were rare in the blue eyed individuals. rs35866166, rs62538956, and rs1289469 were for the first time found to be associated with pigmentary traits, whilst rs1126809 was previously found to be associated with pigmentary variation. To improve prediction of eye colours we suggest that future eye colour prediction models should include rs35866166, rs62538956, rs1289469, and rs1126809.

Physical characteristics of the Uyghurs: anthropometric data from Kashgar

Before the Sui and Tang Dynasties, the Mediterranean type of the European race had been the main ethnic type of the ancient inhabitants of Kashgar. After moving westward to Xinjiang, the Uyghurs of the North Asian Mongolian race started to have long-term integration with other ethnic groups and gradually formed the Uyghurs. At present, the ethnographic characteristics of Uyghur have been a concern for a while. In this study, 560 subjects (273 males and 287 females) were selected and measured using anthropometric methods in Kashgar, the region most representative of the Uyghurs. The study showed that Uyghur individuals have obvious Eurasian characteristics, with South Asian and North Asian features also being identified in this region. However, East Asian type features were rarer in the Uyghur. According to physical characteristics indexes, Kashgar Uyghur males and females are of medium height and heavier weight; with rounder, taller heads and narrower faces that are mesorrhine; they are also wider in chest and shoulder with relatively long trunks. Males have medium head breadth and leg length whereas females possess narrow head breadth and shorter leg length. Among the 13 ethnic groups in China, Uyghur males were found to have a medium nasal root length and extraocular angle as well as reduced Mongolian fold and concave nose. Meanwhile, it is common for Uyghur females to have a high external eye angle, medium concave nose and dorsal rate, a high round ear lobe rate and low nasal base upturn rate. The Uyghur in southern Xinjiang are closer to the East Asian type than the Uyghur in northern Xinjiang. The head and nose features of Uyghur in southern Xinjiang are more similar to those from Mongolia. In case of facial features, the northern Uyghur and Mongolian are relatively close. There is a high incidence of wrinkles on the upper eyelids presented in Uyghur adults, with some people having Mongolian folds, a higher possibility of outer corners than inner corners, and mostly brown eye color. Together this suggests that Uyghur adults have the basic characteristics of the Mongolian race. Uyghur and East Asian ethnic groups are relatively close in face breadth, head length, morphological facial height and head breadth. Due to the fact that Uyghur individuals have rounder and taller heads accompanied by relatively long upper bodies and short legs, they can be considered to have the basic characteristics of an Oriental population. Both the Asian Oriental ethnic group features and Eurasian population characteristics are found in the Uyghur group in terms of their physical type. Among the various types in East Asia, Uyghur adults are closer to the East Asian type, while having certain characteristics of the South Asian and North Asian type. The physical characteristics of the Uyghur may potentially reflect the historical process of multi-ethnic integration.

Morphometric characterization and estimating body weight of two Algerian camel breeds using morphometric measurements.

This study was carried out in order to identify the body measurements of two different Dromedary camel breeds raised in Algeria. The animal material of the study consisted of a total of 115 animals belong to Steppe (n = 55) and Sahraoui (n = 60) camel breeds. Eye and coat colors along with body measurements such as head length, neck length, neck girth, tail length, distance between eyes, distance between ears, body length, withers height, chest girth, and live weight were determined. Least squares means for head length, neck length, neck girth, tail length, distance between eyes, distance between ears, body length, withers height, chest girth, and live weight are found 48.2, 116.9, 65.7, 55.6, 24.1, 22.5, 152.2, 184.5, 141.2cm, and 217.2kg for Steppe and 48.1, 101.2, 56.2, 51.2, 23.4, 18.3, 135.6, 167.3, 176.8cm, and 298.9kg for Sahraoui camel breeds, respectively. The distribution of brown and black eye colors for the Steppe camel breed is as 58.2% and 41.8%, respectively, while all of the Sahraoui camels studied had a brown eye color. The proportional distribution in terms of body color included are coffee, dark coffee, and red colors for 1.8%, 83.6%, and 14.6% in the Steppe camel and 98.3%, 1.7%, and 0.0% for the Sahraoui camel, respectively. As a result, this study concluded that the withers height and chest girth could estimate the body weight in the two breeds of camels with different ages.

Perception of blue and brown eye colours for forensic DNA phenotyping

Eye colour is a prominent visible trait in Europeans and is of significance in forensic genetics. Eye colour is most commonly categorised in a three-category system comprising brown, intermediate, and blue eye colours. However, the general perception of eye colour categories has not been explored. Here, we categorised eye colour based on the subjective evaluation of 442 digital close-up photos of eyes assessed by 30 Danish volunteers. The participants were asked to categorise each eye in a three-category (brown, intermediate, blue) and a two-category (brown, blue) system. We found that the two-category system corresponded best with the perception of eye colour. Disagreements in the eye colour categorisation by at least 10% of the participants were observed for 33% of the eye pictures using the three-category system. In comparison, only 10% of the pictures were categorised differently by at least 10% of participants when using the two-category system. The genetic basis for distinction between blue and brown eye colour primarily depends on a single SNP, rs12913832. Likelihood ratios based on the genotype of rs12913832 and the two-category system were: LR = P(rs12913832:GG|brown)/P(rs12913832:GG|blue) = 0.1, LR = P(rs12913832:AA|brown)/P(rs12913832:AA|blue) = 54, and LR = P(rs12913832:GA|brown)/P(rs12913832:GA|blue) = 19. This SNP is included in the Precision ID Ancestry panel used for ancestry inference, which enables genetic ancestry profiles to be accompanied by prediction of blue or brown eye colour.

HERC2 (rs12913832) and OCA2 (rs1800407) genes polymorphisms in relation to iris color variation in Belarusian population

To develop a specific predictive model for the forensic casework for the Belarusian population, we set up an investigation of the connection between candidate pigmentation SNPs and quantitatively measured eye color of individuals. 471 participants were genotyped for rs12913832 (HERC2) and rs1800407 (OCA2) using TaqMan approach. The obtained data were confirmed by sequencing. The SNP allele distribution in the target regions of the individuals under research was shifted to the G-alleles for both spots: 82% - rs12913832:G, 91% - rs1800407:G. In accordance with the dominant model, brown eye color is characteristic of individuals with allele A (rs12913832:A > G). However, in our research this is not always true for genotypes rs12913832:GA – 41% occurrences were detected with intermediate eye color. Further, we have found the effect of the HERC2-OCA2 variation on the light/dark iris color grade. High values of OR (>53.99) for rs12913832 confirmed their strong relationship with iris color. The impact of rs1800407 (<7.78) was significantly weaker. The logistic regression revealed a low percentage (3.9%) of incorrect predictions: 97.3% of light-eyed individuals and 92.9% of dark-eyed individuals were correctly classified through HERC2(rs12913832)/OCA2(rs1800407) model.

The complementary effect of rs1042522 in TP53 and rs1805007 in MC1R is associated with an elevated risk of cutaneous melanoma in Latvian population.

Genetic factors serve important roles in melanoma susceptibility. Although much genetic variation has been associated with cutaneous melanoma (CM), little is known about the interactions between genetic variants. The current study investigated the joint effect of rs1042522 in the tumour protein 53 (TP53) gene, rs2279744 in the murine double minute-2 (MDM2) gene and several single nucleotide polymorphisms (SNPs) in the melanocortin 1 receptor (MC1R) gene. All of these genes are interconnected in a single signalling pathway that regulates pigmentation. The current study included 479 individuals, of which, 255 were patients with CM and 224 were controls from the Latvian population. Multifaceted analyses of potential interactions between SNPs were performed, whilst taking into account the pigmentation phenotypes of individuals and tumour characteristics (Breslow thickness and ulceration). Univariate analyses revealed a borderline significant association between rs1042522 in the TP53 gene and CM risk. The results also confirmed a known association with rs1805007 in the MC1R gene. The rs1042522 was also selected as a CM risk factor in multivariate models, suggesting an effect that is independent from and complementary to that of rs1805007. The results indicated that these SNPs need to be taken into account when determining melanoma risk. A strong association between CM and red hair was identified for rs1805007, and rs1805008 in the MC1R gene was mainly associated with red hair. An association was also determined between rs2279744 in the MDM2 gene and brown eye colour. No convincing associations were identified between the analysed SNPs and Breslow thickness of tumours or ulcerations.

Eye color prediction using single nucleotide polymorphisms in Saudi population.

BackgroundDNA prediction of eye color represent one application of the externally visible characteristics (EVC), which attained growing interest in the field of DNA forensic phenotyping. This is mainly due to its ability to narrow the pool of suspects without the need to compare any retrieved DNA material from the crime scene to a reference DNA. Several methods and multiplex genetic panel were proposed with variable prediction accuracy between different populations. However, such panel was not previously tested in the Saudi population, nor any populations of the Middle East and North Africa origin.MethodA panel of eleven single nucleotide polymorphisms (SNPs) was tested for their association with three eye colors (brown, hazel, and intermediate) in 80 volunteer Saudi individuals. SNPs and haplotype association test with eye colors were performed to identify the top significant SNPs with the three eye colors. Also, multinomial logistic regression was used to construct the prediction model using a training set of 60 subjects, and a validation set of 20 subjects. The goodness of fit parameter of the model to correctly predicts each eye color as compared to the other was performed.ResultsEye color was significantly associated with rs12913832, rs7170852, and rs916977 that are located within HERC2. SNP rs12913832 was the top significant SNP (p-value = 1.78E−15) that accounted for the association in this region, as the other SNPs were not significant after adjusting for rs12913832. A prediction model containing five SNPs showed high prediction accuracy with Area Under the receiver operating characteristic Curves (AUC) equals to 0.95 and 0.83 for brown and intermediate eye colors, respectively. However, the model’s performance was very low for predicting the hazel eye color with AUC equals 0.75.DiscussionDespite the small sample size of our study, we reported very significant SNP associations with eye color. Our model to predict eye colors based on DNA material showed high accuracy for brown and intermediate eye colors. The eye color prediction-model underperformed for the hazel eye colors, suggesting that larger sample size, as well as more comprehensive set of SNPs, could improve the model-prediction accuracy.