scholarly journals HERC2 and OCA2 genes polimorphisms in relation to the iris color variation of the Belarusian population

Author(s):  
M. N. Shapturenko ◽  
A. V. Kondratiuk ◽  
S. I. Vakula ◽  
M. V. Seredenko (Shinkevich) ◽  
I. G. Gudzievskaya ◽  
...  

The human genetic phenotyping is one of the most intensely developing area of forensic genetics. Externally visible traits, including eye color, can be predicted by analyzing single nucleotide polymorphisms with a high predictive rate. We studied the polymorphisms rs12913832 and rs1800407 in the HERC2 and OCA2 genes, respectively, to evaluate its prognostic availability in relation to the iris pigmentation of the Belarusian population. For this, both eye images and DNA samples were collected from 314 individuals to analyze the key polymorphisms by the TaqMan assay. Our data confirmed a relevance of rs12913832:A>G and rs1800407:G>A in the prediction context. The highest values of the sensitivity (SE = 0.94) and the specificity (SP = 0.90) were obtained for rs12913832, demonstrating the high efficiency of this marker as a classifier of phenotypic groups. The presence of the ancestral dominant allele rs12913832-A causes a dark (brown) iris pigmentation, how- ever, the heterozygous state rs12913832:GA includes a range of mixed variants. The predictive value of rs1800407 for the genetic phenotyping is highly significant (SE = 0.98), but has a low specificity (SP = 0.14), thus rs1800407, not being an effective classifier, can be used as an auxiliary in the eye color predictive model. The analysis of a cumulative impact of the both poly- morphisms on the iris color variation shows their high prospects for the genetic phenotyping of the Belarusian population.

2021 ◽  
Vol 7 (11) ◽  
pp. eabd1239
Author(s):  
Mark Simcoe ◽  
Ana Valdes ◽  
Fan Liu ◽  
Nicholas A. Furlotte ◽  
David M. Evans ◽  
...  

Human eye color is highly heritable, but its genetic architecture is not yet fully understood. We report the results of the largest genome-wide association study for eye color to date, involving up to 192,986 European participants from 10 populations. We identify 124 independent associations arising from 61 discrete genomic regions, including 50 previously unidentified. We find evidence for genes involved in melanin pigmentation, but we also find associations with genes involved in iris morphology and structure. Further analyses in 1636 Asian participants from two populations suggest that iris pigmentation variation in Asians is genetically similar to Europeans, albeit with smaller effect sizes. Our findings collectively explain 53.2% (95% confidence interval, 45.4 to 61.0%) of eye color variation using common single-nucleotide polymorphisms. Overall, our study outcomes demonstrate that the genetic complexity of human eye color considerably exceeds previous knowledge and expectations, highlighting eye color as a genetically highly complex human trait.


Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 2071-2083
Author(s):  
Tony Frudakis ◽  
Matthew Thomas ◽  
Zach Gaskin ◽  
K Venkateswarlu ◽  
K Suresh Chandra ◽  
...  

Abstract To determine whether and how common polymorphisms are associated with natural distributions of iris colors, we surveyed 851 individuals of mainly European descent at 335 SNP loci in 13 pigmentation genes and 419 other SNPs distributed throughout the genome and known or thought to be informative for certain elements of population structure. We identified numerous SNPs, haplotypes, and diplotypes (diploid pairs of haplotypes) within the OCA2, MYO5A, TYRP1, AIM, DCT, and TYR genes and the CYP1A2-15q22-ter, CYP1B1-2p21, CYP2C8-10q23, CYP2C9-10q24, and MAOA-Xp11.4 regions as significantly associated with iris colors. Half of the associated SNPs were located on chromosome 15, which corresponds with results that others have previously obtained from linkage analysis. We identified 5 additional genes (ASIP, MC1R, POMC, and SILV) and one additional region (GSTT2-22q11.23) with haplotype and/or diplotypes, but not individual SNP alleles associated with iris colors. For most of the genes, multilocus gene-wise genotype sequences were more strongly associated with iris colors than were haplotypes or SNP alleles. Diplotypes for these genes explain 15% of iris color variation. Apart from representing the first comprehensive candidate gene study for variable iris pigmentation and constituting a first step toward developing a classification model for the inference of iris color from DNA, our results suggest that cryptic population structure might serve as a leverage tool for complex trait gene mapping if genomes are screened with the appropriate ancestry informative markers.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guanghui An ◽  
Jiongjiong Chen

Abstract Background Mustard (Brassica juncea) is an important economic vegetable, and some cultivars have purple leaves and accumulate more anthocyanins than the green. The genetic and evolution of purple trait in mustard has not been well studied. Result In this study, free-hand sections and metabolomics showed that the purple leaves of mustard accumulated more anthocyanins than green ones. The gene controlling purple leaves in mustard, Mustard Purple Leaves (MPL), was genetically mapped and a MYB113-like homolog was identified as the candidate gene. We identified three alleles of the MYB113-like gene, BjMYB113a from a purple cultivar, BjMYB113b and BjMYB113c from green cultivars. A total of 45 single nucleotide polymorphisms (SNPs) and 8 InDels were found between the promoter sequences of the purple allele BjMYB113a and the green allele BjMYB113b. On the other hand, the only sequence variation between the purple allele BjMYB113a and the green allele BjMYB113c is an insertion of 1,033-bp fragment in the 3’region of BjMYB113c. Transgenic assay and promoter activity studies showed that the polymorphism in the promoter region was responsible for the up-regulation of the purple allele BjMYB113a and high accumulation of anthocyanin in the purple cultivar. The up-regulation of BjMYB113a increased the expression of genes in the anthocyanin biosynthesis pathway including BjCHS, BjF3H, BjF3’H, BjDFR, BjANS and BjUGFT, and consequently led to high accumulation of anthocyanin. However, the up-regulation of BjMYB113 was compromised by the insertion of 1,033-bp in 3’region of the allele BjMYB113c. Conclusions Our results contribute to a better understanding of the genetics and evolution of the BjMYB113 gene controlling purple leaves and provide useful information for further breeding programs of mustard.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sanghamitra Mohanty ◽  
Amelia W Hall ◽  
Prasant Mohanty ◽  
Chintan Trivedi ◽  
Luigi Di Biase ◽  
...  

Introduction: Earlier studies have demonstrated that some AF patients develop spontaneous atrial scarring that leads to genesis and perpetuation of the arrhythmia. However, it is still unclear why it happens in some and not in others. Therefore, we hypothesized that the atrial scar phenotype is associated with certain specific genetic variants and examined the relationship between AF-related single-nucleotide polymorphisms (SNP) and left atrial scar. Methods: Four hundred AF patients (67% male, 62±12 year, left atrial size 45.3±7 mm, 64% non-paroxysmal) undergoing catheter ablation were prospectively enrolled at our center. DNA extraction and genotyping for 16 AF-associated SNPS identified by GWAS study were performed from the collected blood samples using Qiagen QiaAMP 96 well blood kit and TaqMan assay respectively. Three hundred seventy-two DNA samples were available for genotyping. The Hardy-Weinberg equilibrium was assessed using Chi-square analyses. Multivariable logistic model was utilized to identify predictors of LA scar after adjusting for age, gender, LA size, hypertension and diabetes mellitus and odds ratio (OR) and 95% confidence intervals were computed. Results: Of all 16 SNPs, rs3807989 showed a strong inverse association with LA scar at univariate analysis (0.54 [0.348-0.89] p= 0.014) in the overall population. After adjustment for covariates, the association became highly significant indicating a 50% reduction in scar risk (OR 0.50 (0.30-0.83) p=0.007). When stratified by type of AF, rs3807989 genotype predicted a substantially stronger 69% risk-reduction in the non-PAF population (OR 0.31 (0.15-0.62) p=0.0009). Conclusion: The SNP, rs3807989 on chromosome 7p31, was demonstrated to be associated with reduced risk of left atrial scar formation in AF patients. This genetic variant is located in close proximity to the caveolin-1 gene which is known to have an anti-fibrotic role by inhibiting transforming growth factor-β1, a key mediator in the fibrosis process. Therefore, it can be postulated that by some unknown mechanism the candidate chromosomal variant potentially upregulates caveolin-1 function resulting in attenuation of fibrosis and scar formation.


2018 ◽  
Vol 5 (1) ◽  
pp. 37-40
Author(s):  
Seri Mirianti Ishar ◽  
Jeyaganesan Pillay a/l Balaraman ◽  
Muhammad Jefri Mohd Yusof ◽  
Khairul Osman ◽  
Lee Loong Chuen

Human DNA consists of nucleus DNA (nDNA) and mitochondrial DNA (mtDNA). Both are valuable in medicine and forensic genetics but in this project, single nucleotide polymorphisms (SNPs) in mtDNA are used to trace the mutation occurred. Mutations in the sequence of alleles can lead to haplogroup variation and also certain diseases. The purpose of this study is to screen of mutations on alleles G709A, G3496T, and A3537G in Malay population of The National University of Malaysia (UKM) students. These SNPs lie in the ND1 (nitrogen dehydrogenase subunit 1) coding region, and the reports state that these three alleles are prone to mutate. From MitoMap Web site, the mutations of these alleles are reported to have potential in causing several diseases with the collaboration of other SNPs mutation. Allele G709A is reported to have an association with hearing loss and Leber Hereditary Optic Neuropathy (LHON) while allele G3496T is associated to LHON only. Allele A3537G is related to diabetes. A total of 100 DNA samples were collected from Malay students of UKM and preserved on FTA card to be purified later. The concentration of the DNA on the purified FTA card was between 10μM to 20μM. An attempt was made by amplifying those three loci from the genomic DNA. The amplified product was detected and separated using 1% gel electrophoresis. Before sequencing, the PCR products were visualized under UV light using gel documentation system. All PCR products were sequenced to detect the mutation on every single position chosen. From the alignment of sequencing results, allele G709A and allele G3496T showed no mutation. Meanwhile four samples from alleles A3537G has the mutation. From the results obtained, it seems that mutations are rare in all selected alleles. It is recommended to increase the sample size and alleles selected in the future to increase the strength of the study. This study also should be applied to other populations in Malaysia such as Chinese and Indian.  


2019 ◽  
Vol 26 (7) ◽  
pp. 1607-1612
Author(s):  
Jahad Alghamdi ◽  
Manal Amoudi ◽  
Ahmad Ch. Kassab ◽  
Mansour Al Mufarrej ◽  
Saleh Al Ghamdi

2012 ◽  
Vol 62 (3) ◽  
pp. 367-377
Author(s):  
Liang Chi ◽  
Xiaofeng Sun ◽  
Ming Zou ◽  
Huanqi Liu

The melanocortin 1 receptor (MC1R) plays an important role in determining plumage color, and the variants of MC1R have been found to be associated with the color of plumage and skin in both domestic and wild birds. However, the molecular and genetic mechanism for plumage color variation has not been reported in silky fowl, which is a unique subspecies in China with high nutritive value. We sequenced and analyzed the encoding region of MC1R from silky fowl. The predicted coding region of MC1R is 945 bp, which is the same size as the one in Gallus gallus. Six nucleotide polymorphisms that lead to four protein mutations were detected, which were M71T, E92K, S124G and H215P, respectively. Among the four mutations, the S124G mutation is found to be unique to silky fowl. A phylogenetic tree analysis of MC1R from silky fowl and other species of chicken shows a close relationship between silky fowl and Gallus gallus. Furthermore, the eukaryotic expression vector pEGFP-N1-MC1R was constructed, and transfected into goat fibroblasts by means of electroporation. The success of MC1R gene expression in transfected goat fibroblasts makes it possible to develop transgenic animals for further studies.


2008 ◽  
Vol 68 (2) ◽  
pp. 253-256 ◽  
Author(s):  
B Rueda ◽  
J Broen ◽  
O Torres ◽  
C Simeon ◽  
N Ortego-Centeno ◽  
...  

Objectives:Multiple studies indicate the role of the interleukin (IL)-17/IL-23 axis in autoimmune diseases, including systemic sclerosis (SSc). The aim of the current study was to investigate the possible implication of the IL23R gene in SSc susceptibility and/or clinical phenotype.Methods:An initial case–control study in 143 Dutch patients with SSc and geographically matched healthy individuals (n = 246) was carried out and followed by a replication study in a cohort of 365 Spanish patients with SSc and 515 healthy individuals. Seven single nucleotide polymorphisms (SNPs) spanning the IL23R gene were selected and genotyped using a Taqman assay.Results:Using a Dutch cohort of patients with SSc and controls we observed an association between two (rs11209032, rs1495965) of the seven tested SNPs and disease susceptibility (allelic p values: p = 0.02 and p = 0.01 respectively). However, a replication study in an independent Spanish cohort did not confirm these findings and reveal no association of any of the IL23R-tested SNP with disease susceptibility or clinical phenotype. Similarly, a meta-analysis considering both populations did not reveal any significant association. In addition, no association was observed between IL23R genetic variants and SSc clinical phenotypes.Conclusions:Our results suggest that the IL23R gene is not associated with SSc susceptibility or clinical phenotype.


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