Intronic Polymorphism Research Articles

Genome-Wide Association Study of Chronic Dizziness in the Elderly Identifies Loci Implicating MLLT10, BPTF, LINC01224, and ROS1.

Chronic age-related imbalance is a common cause of falls and subsequent death in the elderly and can arise from dysfunction of the vestibular system, an elegant neuroanatomical group of pathways that mediates human perception of acceleration, gravity, and angular head motion. Studies indicate that 27-46% of the risk of age-related chronic imbalance is genetic; nevertheless, the underlying genes remain unknown. The cohort consisted of 50,339 cases and 366,900 controls in the Million Veteran Program. The phenotype comprised cases with two ICD diagnoses of vertigo or dizziness at least 6months apart, excluding acute or recurrent vertiginous syndromes and other non-vestibular disorders. Genome-wide association studies were performed as individual logistic regressions on European, African American, and Hispanic ancestries followed by trans-ancestry meta-analysis. Downstream analysis included case-case-GWAS, fine mapping, probabilistic colocalization of significant variants and genes with eQTLs, and functional analysis of significant hits. Two significant loci were identified in Europeans, another in the Hispanic population, and two additional in trans-ancestry meta-analysis, including three novel loci. Fine mapping revealed credible sets of intronic single nucleotide polymorphisms (SNPs) in MLLT10- a histone methyl transferase cofactor, BPTF- a subunit of a nucleosome remodeling complex implicated in neurodevelopment, and LINC01224- a proto-oncogene receptor tyrosine kinase. Despite the difficulties of phenotyping the nature of chronic imbalance, we replicated two loci from previous vertigo GWAS studies and identified three novel loci. Findings suggest candidates for further study and ultimate treatment of this common elderly disorder.

Prevalence of 4a/4b polymorphic variants of the eNOS gene introne in patients with different types of encephalopathies

Questions related to the disruption of vasoregulatory processes as essential factor in neurological pathology require further study. The leading role in the vasoregulatory mechanisms is played by endothelial NO synthase which gene has 15 allelic variants. Recent data indicated a probable association between eNOS gene polymorphism and cerebrovascular diseases. The aim of the present work was to study the prevalence of the 4a/4b introne polymorphism of the eNOS gene in patients with various types of encephalopathies and to evaluate the influence of a particular genotype of the studied gene on the occurrence and/or progression of encephalopathy. A total of 96 patients with encephalopathies of various genesis: chronic traumatic encephalopathy, chronic alcohol-induced encephalopathy, chronic vascular encephalopathy, post-infectious encephalopathy were involved in the study. The patients received inpatient treatment in the neurological department of “Ternopil Regional Clinical Psychoneurological Hospital”. Molecular and genetic differentiation of the studied gene variants was carried out by allele-specific PCR or PCR-restriction fragment length polymorphism analysis by standard operational protocols. Analysis of the frequency distribution of eNOS gene 4a/4b polymorphic variant showed that 4b allele prevailed among patients with all types of encephalopathies carriers­. Relative to practically healthy individuals the difference was found only in patients with chronic vascular encephalopathy (CVE), among whom about 39% were carriers of the 4a allele. The presence of the 4a allele was shown to increased the risk of CVE occurrence and/or progression by 4.5 times. The results obtained suggest the reasonability to include the 4a/b intron polymorphism of the eNOS gene in a genetic panel to monitor patients CVE. Keywords: 4a/4b introne, encephalopathies, endothelial NO-synthase, eNOS gene polymorphism

The Hoof Color of Australian White Sheep Is Associated with Genetic Variation of the MITF Gene.

Studying the characteristics of mammalian hoof colors is important for genetic improvements in animals. A deeper black hoof color is the standard for breeding purebred Australian White (AUW) sheep and this phenotype could be used as a phenotypic marker of purebred animals. We conducted a genome-wide association study (GWAS) analysis using restriction site associated DNA sequencing (RAD-seq) data from 577 Australian White sheep (black hoof color = 283, grey hoof color = 106, amber hoof color = 186) and performed association analysis utilizing the mixed linear model in EMMAX. The results of GWAS demonstrated that a specific single-nucleotide polymorphism (SNP; g. 33097911G>A) in intron 14 of the microphthalmia-associated transcription factor (MITF) gene was significantly associated with the hoof color in AUW sheep (p = 9.40 × 10-36). The MITF gene plays a key role in the development, differentiation, and functional regulation of melanocytes. Furthermore, the association between this locus and hoof color was validated in a cohort of 212 individuals (black hoof color = 122, grey hoof color = 38, amber hoof color = 52). The results indicated that the hoof color of AUW sheep with GG, AG, and AA genotypes tended to be black, grey, and amber, respectively. This study provided novel insights into hoof color genetics in AUW sheep, enhancing our comprehension of the genetic mechanisms underlying the diverse range of hoof colors. Our results agree with previous studies and provide molecular markers for marker-assisted selection for hoof color in sheep.

Divergent combinations of cis-regulatory elements control the evolution of phenotypic plasticity.

The widespread occurrence of phenotypic plasticity across all domains of life demonstrates its evolutionary significance. However, how plasticity itself evolves and how it contributes to evolution is poorly understood. Here, we investigate the predatory nematode Pristionchus pacificus with its feeding structure plasticity using recombinant-inbred-line and quantitative-trait-locus (QTL) analyses between natural isolates. We show that a single QTL at a core developmental gene controls the expression of the cannibalistic morph. This QTL is composed of several cis-regulatory elements. Through CRISPR/Cas-9 engineering, we identify copy number variation of potential transcription factor binding sites that interacts with a single intronic nucleotide polymorphism. Another intronic element eliminates gene expression altogether, mimicking knockouts of the locus. Comparisons of additional isolates further support the rapid evolution of these cis-regulatory elements. Finally, an independent QTL study reveals evidence for parallel evolution at the same locus. Thus, combinations of cis-regulatory elements shape plastic trait expression and control nematode cannibalism.

Ethnicity-specific association between TERT rs2736100 (A > C) polymorphism and lung cancer risk: a comprehensive meta-analysis

The rs2736100 (A > C) polymorphism of the second intron of Telomerase reverse transcriptase (TERT) has been confirmed to be closely associated with the risk of Lung cancer (LC), but there is still no unified conclusion on the results of its association with LC. This study included Genome-wide association studies (GWAS) and case–control studies reported so far on this association between TERT rs2736100 polymorphism and LC to clarify such a correlation with LC and the differences in it between different ethnicities and different types of LC. Relevant literatures published before May 7, 2022 on ‘TERT rs2736100 polymorphism and LC susceptibility’ in PubMed, EMbase, CENTRAL, MEDLINE databases were searched through the Internet, and data were extracted. Statistical analysis of data was performed in Revman5.3 software, including drawing forest diagrams, drawing funnel diagrams and so on. Sensitivity and publication bias analysis were performed in Stata 12.0 software. The C allele of TERT rs2736100 was associated with the risk of LC (Overall population: [OR] = 1.21, 95%CI [1.17, 1.25]; Caucasians: [OR] = 1.11, 95%CI [1.06, 1.17]; Asians: [OR] = 1.26, 95%CI [1.21, 1.30]), and Asians had a higher risk of LC than Caucasians (C vs. A: Caucasians: [OR] = 1.11 /Asians: [OR]) = 1.26). The other gene models also showed similar results. The results of stratified analysis of LC patients showed that the C allele was associated with the risk of Non-small-cell lung carcinoma (NSCLC) and Lung adenocarcinoma (LUAD), and the risk of NSCLC and LUAD in Asians was higher than that in Caucasians. The C allele was associated with the risk of Lung squamous cell carcinoma (LUSC) and Small cell lung carcinoma(SCLC) in Asians but not in Caucasians. NSCLC patients ([OR] = 1.27) had a stronger correlation than SCLC patients ([OR] = 1.03), and LUAD patients ([OR] = 1.32) had a stronger correlation than LUSC patients ([OR] = 1.09).In addition, the C allele of TERT rs2736100 was associated with the risk of LC, NSCLC and LUAD in both smoking groups and non-smoking groups, and the risk of LC in non-smokers of different ethnic groups was higher than that in smokers. In the Asians, non-smoking women were more at risk of developing LUAD. The C allele of TERT rs2736100 is a risk factor for LC, NSCLC, and LUAD in different ethnic groups, and the Asian population is at a more common risk. The C allele is a risk factor for LUSC and SCLC in Asians but not in Caucasians. And smoking is not the most critical factor that causes variation in TERT rs2736100 to increase the risk of most LC (NSCLC, LUAD). Therefore, LC is a multi-etiological disease caused by a combination of genetic, environmental and lifestyle factors.

Characterization of FLOWERING LOCUS C 5 in Brassica rapa L.

Brassica rapa L., which includes Chinese cabbage, turnip, and pak choi, has more complex flowering time regulation than does Arabidopsis thaliana due to the presence of multiple paralogous flowering time genes. FLOWERING LOCUS C (FLC) is one of the key genes regulating the flowering time, and B. rapa has four FLC paralogs. BrFLC5 on the reference genome is deemed a pseudogene because of a mutation (from G to A) in the splice site of the third intron, but there are some accessions with a G nucleotide in the splice site. In this study, we genotyped 310 B. rapa accessions and found that 19 had homozygous and 81 had heterozygous putative functional BrFLC5 alleles. Accessions of turnip showed the highest proportion with a functional BrFLC5 allele. BrFLC5 acts as a floral repressor when overexpressed in A. thaliana. The BrFLC5 expression level varied in pre-vernalized plants, and this transcriptional variation was not associated with the G/A polymorphism in the third intron. Three accessions having a higher BrFLC5 expression in pre-vernalized plants had a 584-bp insertion in the promoter region. Many regions homologous to this 584-bp sequence are present in the B. rapa genome, and this 584-bp inserted region has tandem duplications of an AT-rich sequence in its central region. The possibility that a high expression of a functional BrFLC5 could contribute to producing premature bolting-resistant lines in B. rapa vegetables is discussed.

PTPN22 intron polymorphism rs1310182 (c.2054-852T>C) is associated with type 1 diabetes mellitus in patients of Armenian descent.

Protein tyrosine phosphatase, nonreceptor type 22 (PTPN22), is an archetypal non-HLA autoimmunity gene. It is one of the most prominent genetic contributors to type 1 diabetes mellitus outside the HLA region, and prevalence of its risk variants is subject to enormous geographic variability. Here, we address the genetic background of patients with type 1 diabetes mellitus of Armenian descent. Armenia has a population that has been genetically isolated for 3000 years. We hypothesized that two PTPN22 polymorphisms, rs2476601 and rs1310182, are associated with type 1 diabetes mellitus in persons of Armenian descent. In this association study, we genotyped the allelic frequencies of two risk-associated PTPN22 variants in 96 patients with type 1 diabetes mellitus and 100 controls of Armenian descent. We subsequently examined the associations of PTPN22 variants with the manifestation of type 1 diabetes mellitus and its clinical characteristics. We found that the rs2476601 minor allele (c.1858T) frequency in the control population was very low (q = 0.015), and the trend toward increased frequency of c.1858CT heterozygotes among patients with type 1 diabetes mellitus was not significant (OR 3.34, 95% CI 0.88-12.75; χ2 test p > 0.05). The control population had a high frequency of the minor allele of rs1310182 (q = 0.375). The frequency of c.2054-852TC heterozygotes was significantly higher among the patients with type 1 diabetes mellitus (OR 2.39, 95% CI 1.35-4.24; χ2 test p < 0.001), as was the frequency of the T allele (OR 4.82, 95% CI 2.38-9.76; χ2 test p < 0.001). The rs2476601 c.1858CT genotype and the T allele correlated negatively with the insulin dose needed three to six months after diagnosis. The rs1310182 c.2054-852CC genotype was positively associated with higher HbA1c at diagnosis and 12 months after diagnosis. We have provided the first information on diabetes-associated polymorphisms in PTPN22 in a genetically isolated Armenian population. We found only a limited contribution of the prototypic gain-of-function PTPN22 polymorphism rs2476601. In contrast, we found an unexpectedly close association of type 1 diabetes mellitus with rs1310182.

P53 Dysregulation in Breast Cancer: Insights on Mutations in the TP53 Network and p53 Isoform Expression.

In breast cancer, p53 expression levels are better predictors of outcome and chemotherapy response than TP53 mutation. Several molecular mechanisms that modulate p53 levels and functions, including p53 isoform expression, have been described, and may contribute to deregulated p53 activities and worse cancer outcomes. In this study, TP53 and regulators of the p53 pathway were sequenced by targeted next-generation sequencing in a cohort of 137 invasive ductal carcinomas and associations between the identified sequence variants, and p53 and p53 isoform expression were explored. The results demonstrate significant variability in levels of p53 isoform expression and TP53 variant types among tumours. We have shown that TP53 truncating and missense mutations modulate p53 levels. Further, intronic mutations, particularly polymorphisms in intron 4, which can affect the translation from the internal TP53 promoter, were associated with increased Δ133p53 levels. Differential expression of p53 and p53 isoforms was associated with the enrichment of sequence variants in p53 interactors BRCA1, PALB2, and CHEK2. Taken together, these results underpin the complexity of p53 and p53 isoform regulation. Furthermore, given the growing evidence associating dysregulated levels of p53 isoforms with cancer progression, certain TP53 sequence variants that show strong links to p53 isoform expression may advance the field of prognostic biomarker study in breast cancer.

Polymorphisms of Fat Mass and Obesity-Associated Gene in the Pathogenesis of Child and Adolescent Metabolic Syndrome.

Childhood metabolic syndrome (MetS) is prevalent around the world and is associated with a high likelihood of suffering from severe diseases such as cardiovascular disease later in adulthood. MetS is associated with genetic susceptibility that involves gene polymorphisms. The fat mass and obesity-associated gene (FTO) encodes an RNA N6-methyladenosine demethylase that regulates RNA stability and molecular functions. Human FTO contains genetic variants that significantly contribute to the early onset of MetS in children and adolescents. Emerging evidence has also uncovered that FTO polymorphisms in intron 1, such as rs9939609 and rs9930506 polymorphisms, are significantly associated with the development of MetS in children and adolescents. Mechanistic studies reported that FTO polymorphisms lead to aberrant expressions of FTO and the adjacent genes that promote adipogenesis and appetite and reduce steatolysis, satiety, and energy expenditure in the carriers. The present review highlights the recent observations on the key FTO polymorphisms that are associated with child and adolescent MetS with an exploration of the molecular mechanisms underlying the development of increased waist circumference, hypertension, and hyperlipidemia in child and adolescent MetS.

A non-coding variant linked to metabolic obesity with normal weight affects actin remodelling in subcutaneous adipocytes.

Recent large-scale genomic association studies found evidence for a genetic link between increased risk of type 2 diabetes and decreased risk for adiposity-related traits, reminiscent of metabolically obese normal weight (MONW) association signatures. However, the target genes and cellular mechanisms driving such MONW associations remain to be identified. Here, we systematically identify the cellular programmes of one of the top-scoring MONW risk loci, the 2q24.3 risk locus, in subcutaneous adipocytes. We identify a causal genetic variant, rs6712203, an intronic single-nucleotide polymorphism in the COBLL1 gene, which changes the conserved transcription factor motif of POU domain, class 2, transcription factor 2, and leads to differential COBLL1 gene expression by altering the enhancer activity at the locus in subcutaneous adipocytes. We then establish the cellular programme under the genetic control of the 2q24.3 MONW risk locus and the effector gene COBLL1, which is characterized by impaired actin cytoskeleton remodelling in differentiating subcutaneous adipocytes and subsequent failure of these cells to accumulate lipids and develop into metabolically active and insulin-sensitive adipocytes. Finally, we show that perturbations of the effector gene Cobll1 in a mouse model result in organismal phenotypes matching the MONW association signature, including decreased subcutaneous body fat mass and body weight along with impaired glucose tolerance. Taken together, our results provide a mechanistic link between the genetic risk for insulin resistance and low adiposity, providing a potential therapeutic hypothesis and a framework for future identification of causal relationships between genome associations and cellular programmes in other disorders.

ZNF804A intronic variant rs1344706 and NGRN rs12807809 genetic polymorphisms and risk of schizophrenia in Bangladesh

BackgroundGenetic polymorphism exerts an undeniable impact on schizophrenia (SCZ) pathogenesis. Two polymorphisms, including rs1344806 of ZNF804A and rs12807809 of NRGN gene have been identified as susceptible candidates bearing the risk of SCZ. The target of this experimental study is to investigate the role of these polymorphisms with SCZ in native Bangladeshi people. MethodsFor this study, 220 schizophrenic patients and 204 non-schizophrenic controls were recruited to perform this investigation. For genotyping, tetra-primer ARMS-PCR technique was applied. The Agarose gel electrophoresis system visualized the final genomic products of the desired size. ResultsFrom the genotypic analysis of ZNF804A rs1344706 polymorphism, it was revealed that the minor allele frequency was noticeably increased in the patients than in the healthy population (42.27% vs. 29.17%). Five genetic models showed significantly increased risk of SCZ, including codominant model 1 (1.56-times), codominant model 2 (3.02-times), dominant model (1.86-times), recessive model (2.43-times), and allele model (1.78-times) (p < 0.05). The over-dominant model also had 1.18 times higher risk for SCZ, although the result could not meet the significance level (p > 0.05). Genotyping of rs12807809 unveiled the presence of a comparatively higher genotypic frequency of the minor allele among the patients than in controls (39.09% vs. 17.65%). Every genetic model under investigation showed significantly increased risk for SCZ– codominant model 1 (2.85-times), codominant model 2 (6.45-times), dominant model (3.44-times), recessive model (4.31-times), over-dominant model (2.10-times), and allele model (3.00-times) (p < 0.05). ConclusionThis experimental study concluded that rs1344806 of ZNF804A and rs12807809 of NRGN SNPs are significantly associated with SCZ in the Bangladeshi population.

Abstract 1490: Exon exclusion of NELF-E produces an anti-tumorigenic truncated isoform in hepatocellular carcinoma

Abstract Overexpression of negative elongation factor E (NELF-E), a subunit of the negative elongation factor (NELF) complex involved in transcription pausing, has been implicated in poor hepatocellular carcinoma (HCC) outcome. We recently discovered an intronic heterozygous single nucleotide polymorphism (SNP), rs79208225 (G&amp;gt;A), near a spliceosome binding site in less than 1% of the general population but ~4% of our HCC cohort. HCC patients with the SNP had significantly longer times till recurrence (p=0.001) and better overall survival (p=0.02) compared to patients without the SNP. Using the minigene assay, we found the SNP causes exon 10 exclusion, which resulted in lower levels of full length NELF-E and the presence of a truncated NELF-E isoform that was not degraded via RNAi surveillance. We hypothesize NELF-E isoform switching is anti-tumorigenic in HCC. To investigate the effects of exon 10 exclusion, we employed antisense oligonucleotides (ASOs). HCC cells treated with ASOs had decreased cell proliferation and colony formation. Moreover, exon 10 exclusion enriched for the truncated NELF-E isoform and decreased full length mRNA and protein expression. Genetic models (CRISPR/cas9) showed similar phenotypes, suggesting that the truncated NELF-E is anti-tumorigenic. Currently, we are investigating the functional role of the truncated NELF-E protein in transcription regulation and the effects of isoform switching in HCC cells as a potential therapeutic strategy for HCCs with elevated NELF-E levels. Citation Format: Laura Reynolds, Ryan Lamm, Anna Barry, Meghan Grim, Kai Zhang, Hien Dang. Exon exclusion of NELF-E produces an anti-tumorigenic truncated isoform in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1490.

A Cross-sectional Study on the Association of KIBRA Genetic Polymorphism with Episodic Memory in North Jordanian Adults

One of the cognitive processes most damaged by aging and thought to be the system most susceptible to neurodegenerative illnesses is episodic memory. Recently, episodic memory function has been linked to a single nucleotide polymorphism (rs17070145) in the ninth intron of the KIBRA gene (kidney and brain expressed gene). This study looked at the relationship between the KIBRA polymorphism (rs17070145) and the episodic memory abilities assessed by the Rey Auditory Verbal Learning Test and Rey Complex Figure Test at various time points (20-minute, 30-minute, 24-hours and 6-month). 112 healthy adult Jordanians between the ages of 18 and 45 were included in the study, and the genotypes at the KIBRA (rs17070145) polymorphic site were identified using the PCR-RFLP method. The outcomes did not reveal any statistically significant any assessment of verbal and visual episodic memory tests and the KIBRA polymorphism. The findings also indicated that KIBRA polymorphism had no statistically significant impact on short-term memory or learning capacity, indicating that KIBRA had no effect on a person's ability to pay attention or concentrate. Additionally, in the Jordanian population, the genotype percentages for KIBRA rs17070145 were: 10.7% for TT, 43.8% for TC, and 45.5% for CC, and the percentage of the T allele was 0.326. The current investigation discovered no statistically significant differences between the Jordanian population and either the European or the South Asian populations in terms of the percentages of alleles and genotypes of the KIBRA rs17070145 gene.

Association of Interactions between Metabolic 'Caretaker' Genes, p53, MDM2, and Tobacco Use with the Risk of Oral Cancer: A Multifactor Dimensionality Reduction Approach.

The present study investigated the association of interactions between gene polymorphisms in metabolic 'caretaker' genes (Phase I: CYP1A1, CYP2E1; Phase II: GSTM1, GSTT1), the cell cycle regulatory gene, p53, along with its negative controller, MDM-2, and the environment variable (tobacco). A nonparametric model, multifactor dimensionality reduction (MDR), was applied to analyse these interactions. This case-control study was carried out on 242 subjects. Genomic DNA was extracted from peripheral blood lymphocytes.11 gene variants with an exposure variable (tobacco use) were analysed using MDR to identify the best locus model for gene-gene and gene-environment interactions. Statistical significance was evaluated using a 1000-fold permutation test using MDR permutation testing software (version 1.0 beta 2). The value of p<0.05 was considered statistically significant. The best three-locus model for gene-gene interaction included two of the p53 gene polymorphisms; rs17878362 (intron 3) and rs1042522 (exon 4) and rs6413432 in the Phase I gene, CYP2E1(DraI). The three-locus model to evaluate the gene-environment interaction included two intronic polymorphisms of the p53 gene, that is, rs17878362 (intron 3) and rs1625895 (intron 6), and rs4646903 in the Phase I gene CYP1A1*2C. The interaction graphs revealed independent main effects of the tobacco and p53 polymorphism, rs1042522 (exon 4), and a significant additive interaction effect between rs17878362 (intron 3) and rs1042522 (exon 4). The nonparametric approach highlighted the potential role of tobacco use and variations in the p53 gene as significant contributors to oral cancer risk. The findings of the present study will help implement preventive strategies in both tobacco use and screening using a molecular pathology approach.

Evaluation of the evolutionary genetics and population structure of Culex pipiens pallens in Shandong province, China based on knockdown resistance (kdr) mutations and the mtDNA-COI gene

BackgroundMosquitoes are important vectors for a range of diseases, contributing to high rates of morbidity and mortality in the human population. Culex pipiens pallens is dominant species of Culex mosquito in northern China and a major vector for both West Nile virus and Bancroftian filariasis. Insecticide application were largely applied to control the mosquito-mediated spread of these diseases, contributing to increasing rates of resistance in the mosquito population. The voltage-gated sodium channel (Vgsc) gene is the target site of pyrethroids, and mutations in this gene cause knockdown resistance (kdr). While these kdr mutations are known to be critical to pyrethroid resistance, their evolutionary origins remain poorly understood. Clarifying the origins of these mutations is potential to guide further vector control and disease prevention efforts. Accordingly, the present study was designed to study the evolutionary genetics of kdr mutations and their association with the population structure of Cx. p. pallens in Shandong province, China.MethodsAdult Culex females were collected from Shandong province and subjected to morphological identification under a dissection microscope. Genomic DNA were extracted from the collected mosquitoes, the Vgsc gene were amplified via PCR and sequenced to assess kdr allele frequencies, intron polymorphisms, and kdr codon evolution. In addition, population genetic diversity and related population characteristics were assessed by amplifying and sequencing the mitochondrial cytochrome C oxidase I (COI) gene.ResultsTotally, 263 Cx. p. pallens specimens were used for DNA barcoding and sequencing analyses to assess kdr allele frequencies in nine Culex populations. The kdr codon L1014 in the Vgsc gene identified two non-synonymous mutations (L1014F and L1014S) in the analyzed population. These mutations were present in the eastern hilly area and west plain region of Shandong Province. However, only L1014F mutation was detected in the southern mountainous area and Dongying city of Shandong Province, where the mutation frequency was low. Compared to other cities, population in Qingdao revealed significant genetic differentiation. Spatial kdr mutation patterns are likely attributable to some combination of prolonged insecticide-mediated selection coupled with the genetic isolation of these mosquito populations.ConclusionsThese data suggest that multiple kdr alleles associated with insecticide resistance are present within the Cx. p. pallens populations of Shandong Province, China. The geographical distributions of kdr mutations in this province are likely that the result of prolonged and extensive insecticide application in agricultural contexts together with frequent mosquito population migrations. In contrast, the low-frequency kdr mutation detected in central Shandong Province populations may originate from the limited selection pressure in this area and the relative genetic isolation. Overall, the study compares the genetic patterns revealed by a functional gene with a neutral marker and demonstrates the combined impact of demographic and selection factors on population structure.

Plant mitochondrial introns as genetic markers - conservation and variation.

Plant genomes are comprised of nuclear, plastid and mitochondrial components characterized by different patterns of inheritance and evolution. Genetic markers from the three genomes provide complementary tools for investigations of inheritance, genetic relationships and phenotypic contributions. Plant mitochondrial genomes are challenging for universal marker development because they are highly variable in terms of size, gene order and intergenic sequences and highly conserved with respect to protein-coding sequences. PCR amplification of introns with primers that anneal to conserved, flanking exons is effective for the development of polymorphic nuclear genome markers. The potential for plant mitochondrial intron polymorphisms to distinguish between congeneric species or intraspecific varieties has not been systematically investigated and is possibly constrained by requirements for intron secondary structure and interactions with co-evolved organelle intron splicing factors. To explore the potential for broadly applicable plant mitochondrial intron markers, PCR primer sets based upon conserved sequences flanking 11 introns common to seven angiosperm species were tested across a range of plant orders. PCR-amplified introns were screened for indel polymorphisms among a group of cross-compatible Citrus species and relatives; two Raphanus sativus mitotypes; representatives of the two Phaseolus vulgaris gene pools; and congeneric pairs of Cynodon, Cenchrus, Solanum, and Vaccinium species. All introns were successfully amplified from each plant entry. Length polymorphisms distinguishable by gel electrophoresis were common among genera but infrequent within genera. Sequencing of three introns amplified from 16 entries identified additional short indel polymorphisms and nucleotide substitutions that separated Citrus, Cynodon, Cenchrus and Vaccinium congeners, but failed to distinguish Solanum congeners or representatives of the Phaseolus vulgaris major gene pools. The ability of primer sets to amplify a wider range of plant species' introns and the presence of intron polymorphisms that distinguish congeners was confirmed by in silico analysis. While mitochondrial intron variation is limited in comparison to nuclear introns, these exon-based primer sets provide robust tools for the amplification of mitochondrial introns across a wide range of plant species wherein useful polymorphisms can be identified.

VNTR Polymorphism in the Intron 5 of SIRT3 and Susceptibility to Breast Cancer.

Breast cancer recurrence and metastasis are associated with alterations in the cellular stress responses that influence tumour signalling. Sirtuin3 (SIRT3), a mitochondrial deacetylase is the regulator of mitochondrial metabolism and oxidative stress affecting tumour cell responses. Genetic variants or dysregulation of SIRT3 was known to associate with poor prognosis of recurrence and relapse in few cancers. The current case-control study was conducted in Hyderabad, India. A total of 200 primary female breast cancer cases were recruited, irrespective of age and clinical subtype. However, secondary or recurrent breast cancer cases were excluded from the study. A total of 202 age and gender-matched healthy controls without any familial inheritance of either breast or other cancer and having similar ethnicity as cases were recruited. The blood samples of both cases and controls were collected from Nizam's Institute of Medical Sciences (NIMS), Hyderabad. Our study is an attempt to evaluate the association of SIRT3 VNTR polymorphism in intron 5 with the development and progression of breast cancer by PCR-based genotyping. Result: The statistical analysis of the results with respect to epidemiological and clinical phenotypes revealed significant association of 0R allele and 0R/0R genotype with breast cancer risk (p<0.01). The odds ratios also were found to be significant i.e., 0R/0R [OR(CI): 2.67(1.54-4.65); p=0.000005] genotype. Also, the epidemiological and clinical variables have shown significant association with the risk of onset of the disease. Therefore, the influence of lack of repeats at intron 5 harbouring enhancer site on altered expression of SIRT3 might confer increased susceptibility to breast cancer. The VNTR polymorphism in the intron 5 region of SIRT3 gene could serve as a molecular marker for detection of breast cancer onset. Further studies are warranted to study the prognostic and therapeutic significance of this SIRT3 polymorphism.

FOXO3A-short is a novel regulator of non-oxidative glucose metabolism associated with human longevity.

Intronic single-nucleotide polymorphisms (SNPs) in FOXO3A are associated with human longevity. Currently, it is unclear how these SNPs alter FOXO3A functionality and human physiology, thereby influencing lifespan. Here, we identify a primate-specific FOXO3A transcriptional isoform, FOXO3A-Short (FOXO3A-S), encoding a major longevity-associated SNP, rs9400239 (C or T), within its 5' untranslated region. The FOXO3A-S mRNA is highly expressed in the skeletal muscle and has very limited expression in other tissues. We find that the rs9400239 variant influences the stability and functionality of the primarily nuclear protein(s) encoded by the FOXO3A-S mRNA. Assessment of the relationship between the FOXO3A-S polymorphism and peripheral glucose clearance during insulin infusion (Rd clamp) in a cohort of Danish twins revealed that longevity T-allele carriers have markedly faster peripheral glucose clearance rates than normal lifespan C-allele carriers. In vitro experiments in human myotube cultures utilizing overexpression of each allele showed that the C-allele represses glycolysis independently of PI3K signaling, while overexpression of the T-allele represses glycolysis only in a PI3K-inactive background. Supporting this finding inducible knockdown of the FOXO3A-S C-allele in cultured myotubes increases the glycolytic rate. We conclude that the rs9400239 polymorphism acts as a molecular switch which changes the identity of the FOXO3A-S-derived protein(s), which in turn alters the relationship between FOXO3A-S and insulin/PI3K signaling and glycolytic flux in the skeletal muscle. This critical difference endows carriers of the FOXO3A-S T-allele with consistently higher insulin-stimulated peripheral glucose clearance rates, which may contribute to their longer and healthier lifespans.

Association between Alu insertion/deletion polymorphism in intron 8 of human tissue plasminogen activator gene (PLAT) and risk of age-related macular degeneration

Background/Aim: Age-related macular degeneration (AMD) is major reason of blindness in human. Plasminogen is converted to plasmin by tissue plasminogen activator protein (PLAT, formerly known as TPA). A polymorphism in intron 8 of PLAT gene has been reported, either with (insertion) or without (deletion) a 311 bp Alu sequence. This polymorphism is associated with plasma levels of glycoprotein t-PA. t-PA is expressed in the retina and is involved in the development of the eye. It can be hypothesised that the PLAT polymorphism may be correlated with AMD. Therefore, the current study was conducted. Methods: A total of 121 AMD patients and 108 healthy subjects were included in the study. Genotyping was performed by PCR. The strength of the association between AMD and polymorphism was expressed by estimating the odds ratio (OR). Results: There was a significant relationship between the Del/Del genotype and susceptibility to AMD (OR = 2.25, 95 % CI = 1.07-4.69, p = 0.031). After adjusting for various factors such as age, smoking habit and workplace, a similar relationship was obtained (OR = 2.51, 95 % CI = 1.01-6.23, p = 0.049). Conclusions: The homozygosity of the Del allele was found to increase the susceptibility to AMD. This polymorphism may contribute to the risk of AMD in population.

THE ROLE OF HEREDITARY PREDISPOSITION (POLYMORPHIC MARKERS OF GLUTATHIONE-S-TRANSFERASE, CATALASE, ENDOTHELIAL NITROGEN OXIDE SYNTHASE GENES) AND SOME ADVERSE ENVIRONMENTAL FACTORS IN THE DEVELOPMENT OF BRONCHO-OBSTRUCTIVE PATHOLOGY IN CHILDREN LIVING IN RADIOACTIVELY CONTAMINATED AREAS.

summarizing the results of many years of research by the authors on the influence of gene polymorphisms encoding xenobiotic biotransformation enzymes (GSTТ1, GSTM1, GSTР1), antioxidant protection (С^262Т of the catalase gene), endothelial nitric oxide synthase (4a/4b VNTR polymorphism of the eNOS gene), and some environmental factors on the occurrence of broncho-obstructive disorders and the development of bronchial asthma in children, residents of radioactively contaminated areas. The examined school-aged children were residents of radioactively RCA who had no clinical signs of respiratory pathology. Deletion polymorphism of catalase gene (CAT C^262T), polymorphism of glutathione-S-transferase gene (GSTТ1, GSTM1, GSTР1) and the polymorphism in the 4th intron (4a/4b) of the eNOS gene were studied in the molecular genetics laboratory of the State Institution «Reference Center for Molecular Diagnostics of Public Health Ministry of Ukraine». Molecular genetic studies were performed by polymerase chain reaction. The study of the ventilation lung capacity was carried out by the method of computer spirometry based on the data of the «flow-volume» loop analysis. A pharmacological inhalation test with a bronchodilator drug which affects the β2-adrenergic receptors of the lungs was used to detect early changes in the ventilatory lung capacity - bronchial hyperreactivity. One of the leading mechanisms, due to which the implementation of hereditary predisposition to bronchial asthma in children living in radioactively contaminated areas is the polymorphism of certain genes of glutathione-S-transferase, catalase, endothelial nitric oxide synthase. With such polymorphic variants of the GST genes, isoforms of enzymes with reduced activity are produced, which limits their ability to effectively neutralize free radicals, which are formed in excess when free radical oxidation processes are activated due to the constant intake of radionuclides with a long half-life into the body of children. Unfavorable factors that increase the risk of developing broncho-obstructive disorders and the likelihood of their implementation in the form of bronchial asthma in children, residents of radioactively contaminated areas, have been identified. It has been established that among them the leading role is played by hereditary predisposition to this disease. On the part of the child, such negative factors were unfavorable conditions of intrauterine development, the presence of signs of exudative-catarrhal diathesis, manifestations of allergies and frequent respiratory diseases from the first months of life.