ABSTRACT
To elucidate the genes responsible for constitutive human skin color, we measured the extent of skin pigmentation in the buttock, representative of lifelong non-sun-exposed skin, and conducted a gene mapping study on skin color in an isolated Mongolian population composed of 344 individuals from 59 families who lived in Dashbalbar, Mongolia. The heritability of constitutive skin color was 0.82, indicating significant genetic association on this trait. Through the linkage analysis using 1,039 short tandem repeat (STR) microsatellite markers, we identified a novel genomic region regulating constitutive skin color on 11q24.2 with an logarithm of odds (LOD) score of 3.39. In addition, we also found other candidate regions on 17q23.2, 6q25.1, and 13q33.2 (LOD > or = 2). Family-based association tests on these regions with suggestive linkage peaks revealed ten and two significant single nucleotide polymorphisms (SNPs) on the linkage regions of chromosome 11 and 17, respectively. We were able to discover four possible candidate genes that would be implicated to regulate human skin color: ETS1, UBASH3B, ASAM, and CLTC.
Subject(s)
Adolescent , Adult , Child , Female , Humans , Male , Young Adult , Asian People/genetics , Chromosome Mapping , Color , Genome-Wide Association Study , Mongolia , Pedigree , Polymorphism, Single Nucleotide , Skin/metabolism , Skin PigmentationABSTRACT
Objective: To conduct a numerical taxonomy research on the origin plants of Fructus Xanthii and to identify this crude drug, so as to provide evidence for the classification, identification and germplasm optimization of Xanthium genus. Methods: Fruits of Xanthium plants from 25 populations in China were collected and cultivated in the same location. Their growing conditions and morphological characteristics were observed after seedling emergence. And 20 taxonomic characters of the plants such as growth cycle, height of the whole plant, length of leafstalk, length and density of involucre, thorn, length of beak and color of ripe fruits, etc. were selected for detailed observation, recording and analysis. Original data matrix X= {Xii} 25×20 was established by means of 25 operational taxonomic units(OTU) and related 20 groups of characteristic data. The established matrix was analyzed using hierarchical cluster analysis on SPSS 13.0 software. Results and Conclusion: The origin plants of Fructus Xanthii from 25 populations of China fell into four groups, largely consistent with the morphological identification results of this study. The first group was identified as Xanthium sibiricum, the second as X. mongolicum, the: third as X. sibiricum var. subinerme, and the fourth was temporarily named as Shenzhen-type cocklebur Xanthium sp.. The Shenzhen-type cocklebur was special in some taxonomic characters and was possibly a cultivated variety of Xanthium genus. The origin plants of Fructus Xanthii in China can be systematized into 3 species and 1 type, which has been added to the existing taxonomic criteria. The cluster analysis method in this study can be applied for discrimination of Xanthium plants and crude drugs.
ABSTRACT
The QTc interval is a complex quantitative trait and a strong prognostic indicator of cardiovascular mortality in general, healthy people. The aim of this study was to identify non-genetic factors and quantitative trait loci that govern the QTc interval in an isolated Mongolian population. We used multiple regression analysis to determine the relationship between the QTc interval and non-genetic factors including height, blood pressure, and the plasma lipid level. Whole genome linkage analyses were performed to reveal quantitative trait loci for the QTc interval with 349 microsatellite markers from 1,080 Mongolian subjects. Among many factors previously known for association with the QTc interval, age, sex, heart rate, QRS duration of electrocardiogram and systolic blood pressure were also found to have influence on the QTc interval. A genetic effect for the QTc interval was identified based on familial correlation with a heritability value of 0.31. In a whole genome linkage analysis, we identified the four potential linkage regions 7q31-34, 5q21, 4q28, and 2q36.