Are the beta-adducin C1797T polymorphism and gamma-adducin A386G polymorphism associated with essential hypertension in Yi and Hani populations?
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Biomedical subjects
Publications and source records attributed to Haijing Yu.
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A transmembrane protein gene, c1orf37-dup, was identified as a young gene specific to humans. It was derived from the conserved c1orf37 gene through retroposition after the divergence of human and chimpanzee. This gene has evolved rapidly driven by positive Darwinian selection as evident from a significantly high ratio of non-synonymous substitution rate to synonymous substitution rate (K(a)/K(s)=2.08) between the new c1orf37-dup and the parental c1orf37 genes. Population genetics analysis disclosed a very low level of polymorphism in the c1orf37-dup gene and its neighboring regions, thus providing support for the occurrence of a recent selective sweep. The GFP experiments revealed that it encodes a transmembrane protein associated with cell membranes. Non-random distribution of amino acid changes indicates the C1ORF37-DUP protein may have evolved diverged functions in the presumably functionally important N-terminal region in the cytoplasm and the extracellular loop. These lines of evidence support that the functional adaptation of c1orf37-dup has occurred in humans. Unlike its ubiquitously expressed parental gene, c1orf37-dup expresses selectively in several human tissues including brain. It is suggested that c1orf37-dup encodes a novel transmembrane protein in humans which potentially endows new properties to cell surface interactions.
Polydactyly is one of the most common forms of congenital malformation in humans, and is displayed by 119 disorders. Crossed polydactyly (CP) is defined as the coexistence of preaxial and postaxial polydactyly with a difference in the axes of polydactyly between the hands and feet. In an effort to map the gene responsible for CP, we studied a seven-generation Chinese family of 56 individuals, 28 of whom were affected. A thorough search with highly informative polymorphic markers showed no recombination among the affected members with the markers on chromosome 7p15-q11.23, but no linkage with chromosomes 2q31, 7q36, 13q, and 19p. Mutation analysis showed a substitution mutation of 1927C --> T in exon 12 of the GLI3 gene, which is predicted to pretruncate the GLI3 protein. This mutation has variable phenotypes of polydactyly, indicating that other genetic factors also contribute to the diversity of polydactyly phenotypes. Our results increase the phenotypic spectrum caused by GLI3 mutations and are important for the analysis and understanding of the etiology of these limb malformations.
OBJECTIVE: The human beta2-adrenergic receptor (ADRB2) gene is a candidate for contributing to the pathophysiology of essential hypertension. The aims of the present study were to investigate the associations of differing single nucleotide polymorphisms (SNPs) and haplotypes of the ADRB2 gene promoter and coding regions with essential hypertension in genetically homogeneous Hani and Yi minority groups that are non-Han Chinese. METHODS: Four SNPs in the regulatory and seven SNPs in the coding region were genotyped in 271 essential hypertension individuals and 267 controls, and eight haplotypes in the regulatory and five haplotypes in the coding region were determined and tested for association using the likelihood test statistic. RESULTS: There were significant associations of essential hypertension with separate SNPs located in both the regulatory and coding regions in the Yi minority group. In contrast, no associations of essential hypertension were detected with any of single SNPs in the Hani minority group. There is a significant difference in haplotype frequency distributions between the hypertensive participants and the controls in two groups (P < 10). CONCLUSION: The results indicate that variants at the ADRB2 locus may play a role in the pathophysiology of hypertension specifically in the Yi minority group.
BACKGROUND: Although many arguments have been raised on the role of heredity in the etiology of acne, the relevant genetic elements in the pathogenesis of the disease are not well established. OBJECTIVE: The aim of our study was to evaluate the association between a genetic polymorphism in the promoter region of the CYP17 gene and the development of acne. METHODS: 206 acne patients and 200 controls were included in the study. A polymerase chain reaction (PCR) sequencing technique was used to reveal a CYP17 gene polymorphism in its promoter region. A chi2 test was used for data analysis. RESULTS: CYP17 -34T/C polymorphism was found and the frequency distribution of the C/C homozygotes and C allele in the male patients with severe acne (33.3 and 60.9%, respectively) were statistically significantly different from those of the control samples (18.2 and 46.6%; p < 0.05). No significant difference was observed between the female patients, mild + moderate male patients and their controls, respectively. CONCLUSION: The CYP17 -34C/C homozygote Chinese men are at a significantly increased risk of developing severe acne.
BACKGROUND: Aldosterone synthase (CYP11B2) is a key enzyme in the biosynthesis of aldosterone. Recently, a C-344T polymorphism in the promoter region of the CYP11B2 gene has been reported to be in association with high blood pressure. We investigated the association between this polymorphism and essential hypertension in Hani (n=305 individuals) and Yi (n=233 individuals) minorities of China. METHODS: CYP11B2 genotyping with polymerase chain reaction-restriction fragment length polymorphism was performed in 267 normotensive subjects and 271 essential hypertensive subjects. At the same time, the T(-344)C polymorphism detection in 33 subjects was also performed by sequencing. RESULT: The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Hani population were TT: 0.729 vs. 0.610; CT + CC: 0.271 vs. 0.390, respectively. The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Yi population were TT: 0.612 vs. 0.475; CT + CC: 0.388 vs. 0.525, respectively. The frequency of CC + CT genotype in the essential hypertensive group was significantly higher than that in the normotensive controls in both Hani and Yi populations (P<0.05). CONCLUSION: The -344C allele of the CYP11B2 may play a role in genetic predisposition to developing essential hypertension in Hani and Yi minorities of China.
Gene number difference among organisms demonstrates that new gene origination is a fundamental biological process in evolution. Exon shuffling has been universally observed in the formation of new genes. Yet to be learned are the ways new exons originate and evolve, and how often new exons appear. To address these questions, we identified 2695 newly evolved exons in the mouse and rat by comparing the expressed sequences of 12,419 orthologous genes between human and mouse, using 743,856 pig ESTs as the outgroup. The new exon origination rate is about 2.71 x 10(-3) per gene per million years. These new exons have markedly accelerated rates both of nonsynonymous substitutions and of insertions/deletions (indels). A much higher proportion of new exons have K(a)/K(s) ratios >1 (where K(a) is the nonsynonymous substitution rate and K(s) is the synonymous substitution rate) than do the old exons shared by human and mouse, implying a role of positive selection in the rapid evolution. The majority of these new exons have sequences unique in the genome, suggesting that most new exons might originate through "exonization" of intronic sequences. Most of the new exons appear to be alternative exons that are expressed at low levels.
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Gene fission and fusion, the processes by which a single gene is split into two separate genes and two adjacent genes are fused into a single gene, respectively, are among the primary processes that generate new genes. Despite their seeming reversibility, nothing is known about the mechanism of gene fission. Because the nucleotide sequences of fission genes record little about their origination process, conventional analysis of duplicate genes may not be powerful enough to unravel the underlying mechanism. In a survey for young genes in species of the Drosophila melanogaster subgroup using fluorescence in situ hybridization, we identified a young gene family, monkey king, whose genesis sheds light on the evolutionary process of gene fission. Its members originated 1-2 million years ago as retroposed duplicates and evolved into fission genes that separately encode protein domains from a multidomain ancestor. The mechanism underlying this process is gene duplication with subsequent partial degeneration.