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B Alleles (b + allele)
Selected AbstractsThe role and frequency of glutathione s-transferase P1 polymorphism in Iranian patients affected with reflux esophagitisDISEASES OF THE ESOPHAGUS, Issue 7 2010N. Zendehdel SUMMARY Reflux esophagitis is a common complication of the gastroesophageal reflux disease. Glutathione s-transferases (GSTs) have important role in the protection of cells from the products of oxidative stress. GSTP1*B allele has a correlation with susceptibility to several diseases. In this case-control study, the role and frequency of GSTP1 polymorphism was evaluated in Iranian patients with erosive reflux esophagitis. Seventy patients with erosive reflux esophagitis and 75 normal individuals were enrolled in this study. The grade of esophagitis was determined via endoscopy. DNA was extracted from venous blood of each subject using the salting out method. GSTP1 genetic polymorphisms were detected using the polymerase chain reaction restriction fragment length polymorphism method. There was a significant difference in GSTP1 genotype frequency between patients and normal groups (P= 0.006). Also, in the patient group, the grade B of esophagitis was significantly associated with variant GSTP1 genotype (P= 0.028). The rate of throat pain symptom was higher in the no-variant group (P < 0.036). The GSTP1*B allele frequency in Iranian normal groups is similar to Orientals. Reflux esophagitis are more commonly found in variant (*B/*B and *A/*B) GSTP1 genotypes. In addition, GSTP1 polymorphism is correlated with a higher grade of esophagitis. [source] Heat shock protein gene 70-2 polymorphism is differentially associated with the clinical phenotypes of ulcerative colitis and Crohn's diseaseJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2007Su Y Nam Abstract Background and Aim:, A single nucleotide polymorphism in heat shock protein 70-2 (HSP70-2) has been shown to be associated with a severe clinical course in Crohn's disease (CD), but it is not known if such a relationship exists in ulcerative colitis (UC). The aim of the present study was to identify associations between the HSP70-2 polymorphism and the clinical courses of CD and UC in Koreans. Methods:, Restriction fragment length polymorphism analysis was performed for HSP70-2 polymorphisms using the PstI-cleavage site present in the B allele but not in the A allele of the DNA obtained from 101 patients with CD, 144 patients with UC, and 245 age- and sex-matched healthy controls. Study subjects were classified by disease behavior, severity and extent of disease. Results:, In CD, multivariate analysis showed that the AA genotype of HSP70-2 polymorphisms was associated with non-perforating disease (OR 10.10, 95% CI 1.66,15.38) and male sex (OR 3.56, 95% CI 1.04,12.23), and that the BB genotype was associated with severe CD (OR 12.03, 95% CI 1.60,101.56). In contrast, multivariate analysis for UC showed that the AA genotype was associated with severe UC (OR 2.02, 95% CI 1.34,3.03). Conclusions:, CD patients with BB genotype of HSP70-2 polymorphism tend to experience a more severe clinical course and allele A is associated with more severe UC. HSP70-2 polymorphism may be used to predict CD and UC phenotypes, which can illuminate immunological differences in CD and UC. [source] Mannose-binding lectin gene polymorphism and resistance to therapy in women with recurrent vulvovaginal candidiasisBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2008GGG Donders Precis, Women with recurrent vulvovaginal candidiasis (RVC) due to a polymorphism in codon 54 of the MBL2 gene respond better to fluconazole maintenance therapy than do women with other underlying causes. Objective, To explain differences in response rates to maintenance therapy with fluconazole in women suffering from RVC by evaluating associations with a polymorphism in the gene coding for mannose-binding lectin (MBL). Design, Follow-up study, neted case-control group. Setting, Women attending vulvoginitis clinic for RVC. Population, Women participating in a multicentric study in Belgium with a degressive dose of fluconazole for RVC (the ReCiDiF trial) were divided into good responders, intermediate responders and nonresponders according to the number of relapses they experienced during therapy. From 109 of these women with adequate follow-up data, vaginal lavage with 2 ml of saline were performed at the moment of a proven acute attack at inclusion in the study, before maintenance treatment was started. A buccal swab was obtained from 55 age-matched women without a history of Candida infections, serving as a control group. Methods, Extracted DNA from buccal or vaginal cells was tested for codon 54 MBL2 gene polymorphism by polymerase chain reaction and endonuclease digestion. Main outcome measures, Frequency of MBL2 condon 54 allele B in women with optimal or poor response to maintenance therapy in composition with controls. Results, Women (n = 109) suffering from RVC were more likely to carry the variant MBL2 codon 54 allele B than control women (20 versus 6.6%, OR 3.4 [95% CI 1.3,8.2], P = 0.01). B alleles were present in 25% of the 36 women not suffering from any recurrence during the maintenance therapy with decreasing doses of fluconazole (OR 4.9 [95% CI 1.9,12.5], P = 0.0007 versus controls), in 20% of the 43 women with sporadic recurrences (OR 3.6 [95% CI 1.4,9.2], P = 0.007 versus controls) and in 15% of the 30 women who had to interrupt the treatment regimen due to frequent relapses (P = 0.097 versus controls). Conclusions, The MBL2 codon 54 gene polymorphism is more frequent in Belgian women suffering from RVC than in controls. The presence of the B allele is associated with a superior response to fluconazole maintenance therapy as compared with RVC patients without this polymorphism. We conclude that RVC due to deficient MBL production is more easily helped with antifungal medication than is RVC due to some other mechanism. [source] Apolipoprotein E and Paraoxonase 1 polymorphisms are associated with lower serum thyroid hormones in postmenopausal womenCLINICAL ENDOCRINOLOGY, Issue 2 2009Irene Lambrinoudaki Summary Objective, Autoimmune thyroiditis and overt or subclinical hypothyroidism have been associated with increased prevalence of cardiovascular disease (CVD). Design, Cross-sectional investigation of the association between gene polymorphisms related to CVD with thyroid function and autoimmunity. Patients, In total 84 healthy postmenopausal women aged 49,69 years. Measurements, FT3, FT4, anti-TPO and anti-TG were assessed in the sera of participants. The following polymorphisms were assessed from peripheral lymphocyte DNA: Apolipoprotein E E2/E3/E4, paraoxonase 1 A/B, Glycoprotein IIIa leu33pro, MTHFR ala222val, ApoBarg3500gln, plasminogen activator inhibitor 1 4G/5G, cholesterol 7-, hydroxylase A204C and cholesterol ester transfer protein B1/B2. Results, A statistically significant correlation was found between Apolipoprotein E and paraoxonase1 polymorphisms and serum thyroid hormones: carriers of the E2 or E4 allele of the ApoE gene had lower levels of FT4 (P = 0·0005) than women with the E3/E3 genotype. Carriers of the B allele of paraoxonase 1 gene had lower levels of FT3 compared to women with the wild-type genotype (P = 0·047). A statistically significant positive association (P = 0·049) was also observed between anti-TG antibodies and the presence of the E2 allele of the Apolipoprotein E gene. Conclusions, Polymorphisms of apolipoprotein E and paraoxonase 1 are associated with different levels of thyroid hormone and anti-Tg antibody levels in the study population in this pilot study. The mechanism underlying this association remains to be elucidated. [source] The vitamin D receptor gene variant is associated with the prevalence of Type 2 diabetes mellitus and coronary artery diseaseDIABETIC MEDICINE, Issue 10 2001J. R. Ortlepp Abstract Aims, Vitamin D can influence lipolysis and insulin secretion. A common genetic polymorphism of the vitamin D receptor, which has been found to be associated with bone mineral density, has also been reported to be associated with insulin-dependent diabetes mellitus. To test the influence of the vitamin D receptor polymorphism on the prevalence of Type 2 diabetes mellitus and coronary artery disease we studied a population of high-risk patients, who were referred to our clinic for diagnostic coronary angiography. Methods, A total of 293 patients considered at high risk for coronary artery disease because of angina pectoris and known hypercholesterolaemia underwent diagnostic coronary angiography. The BsmI vitamin D receptor polymorphism was analysed by polymerase chain reaction. Results, Prevalence of Type 2 diabetes mellitus and coronary artery disease was gradually dependent on the number of B alleles (BB 28%, Bb 13%, bb 8% for Type 2 diabetes mellitus, P = 0.002; BB 88% Bb 72%, bb 66% coronary artery disease, P = 0.01). Patients with the BB genotype had an odds ratio of 3.64 (95% confidence interval 1.53,8.55, P = 0.002) to have Type 2 diabetes mellitus compared with patients with the bb genotype. Conclusions, The genotype of the vitamin D receptor polymorphism determines the prevalence of Type 2 diabetes mellitus and coronary artery disease in a high-risk cohort population. Diabet. Med. 18, 842,845 (2001) [source] HLA class I polymorphism in a Moroccan population from CasablancaINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 3 2002F. Choukri Summary We have studied the distribution of HLA-A and -B alleles and haplotypes by sequence-specific primer amplification in a sample of 100 unrelated healthy individuals belonging to both Berber and Arabic-speaking groups from the region of Casablanca in Morocco. Among the 17 HLA-A and 23 HLA-B alleles observed, the most frequent were HLA-A2 (21%), -A1 (11%), -A3 (10%), -B44 (11.4%), -B50 (9.9%), -B5(8.5%) and -B35 (6.5%). Six two-locus haplotypes were observed with a frequency above 5%: A2-B50 (9.6%), A23-B44 (7.4%), A2-B15 (6.4%), A68-B39 (5.3%), A1-B51 (5.3%) and A68-B44 (4.3%). Our data confirm that, on the basis of genetic distances, the majority of present-day North Africans from Morocco are closely related to Berbers and also to Iberians. They cluster apart from Middle-Eastern Mediterranean populations, and show greater genetic distances to Eastern and other Mediterranean populations. This study will serve as a reference for further anthropological studies, as well as studies of HLA and disease associations. [source] Lipid metabolism and occurrence of post-percutaneous transluminal coronary angioplasty restenosis: role of cholesteryl ester transfer protein and paraoxonase/arylesteraseJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2003R. Y. L. Zee Summary., Plasma lipid metabolic and transfer processes have recently been suggested to play an important role in the development of early restenosis, a major complication of percutaneous transluminal coronary angioplasty (PTCA); in particular, the common variants of genes for cholesteryl ester transfer protein (CETP) and paraoxonase (PONA) have been implicated. We had the opportunity to investigate this question in a large, prospective cohort characterized by quantitative coronary angiography in all subjects. The CETP-TaqIB (intron 1), CETP-MspI (intron 8), and PONA-AlwI (exon 2) polymorphisms were characterized in a cohort of 779 patients of whom 342 (,cases') had developed restenosis (as defined by >,50% loss of lumen compared with immediate postprocedure results) at repeat angiography at 6 months post PTCA. Selected frequencies for CETP B1 and B2 alleles (absence/presence of TaqIB site) were 0.65 and 0.35 (cases) and 0.65 and 0.35 (controls), respectively; frequencies for CETP M1 and M2 alleles (absence/presence of MspI site) were 0.20 and 0.80 (cases), 0.21 and 0.79 (controls), respectively; frequencies for PONA A and B alleles (absence/presence of AlwI site) were 0.73 and 0.27 (cases), 0.72 and 0.28 (controls), respectively. All observed genotype frequencies were in Hardy,Weinberg equilibrium. There was no evidence for gene,gene interaction, or an association between genotype and restenosis or degree of lumen loss (adjusted for covariates). Our data, collected in the largest study of its kind so far, indicate that the common variants for CETP and PONA are not associated with incidence of restenosis after PTCA, and are therefore not useful markers for risk assessment. [source] Enhancement of Immunogenicity of Jeg3 Cells by Ectopic Expression of HLA-A*0201 and CD80AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2003Serpil Koc Problem: The choriocarcinoma cell line Jeg3 suppresses immunity in vitro by secretion of soluble factors like leukemia inhibitory factor suppressing leukocyte activation. The cells lack expression of classical human leukocyte antigen (HLA)-A and -B alleles but express some HLA-C, and non-classical HLA-G and -E. Upon binding to killing inhibitory receptor on natural killer (NK) cells, HLA-G prevents activation of cytolytic activity. We investigated whether Jeg3 cells are capable of immune stimulation after complementation with classical HLA and T cell costimulatory signal CD80. Method of study: Jeg3 cells were transduced to express HLA-A*0201 and/or CD80. Parental Jeg3 or transfectants Jeg3-A2, Jeg3-CD80 or Jeg3-CD80-A2 were used to stimulate allogeneic resting and activated peripheral blood lymphocytes (PBL). The different cell lines were loaded with a HLA-A2-restricted Epstein-Barr virus (EBV) recall antigen peptide epitope and antigen presenting ability was examined. T cell lines specific for Jeg3 and transfectants were generated from HLA-A2 matched and nonmatched donors and compared for expansion, phenotypes and cytolytic activity. Results: While all Jeg3 cell lines induced only marginal proliferation of resting T cells, phytohemagglutinin (PHA)-activated T cells were stimulated by CD80 or CD80-A2 expressing Jeg3. Only the transfectant Jeg3-CD80-A2 was capable of specific T cell stimulation by EBV recall antigen presentation. T cell lines of HLA-A2 non-matched donors stimulated with the Jeg3 transfectants showed significant expansion only when HLA-A2 and the costimulus CD80 were present. T cells from HLA-A2 positive donors did not expand significantly or differentially. No NK cells grew under any condition. In Jeg3-CD80-A2 stimulated T cells lines CD8+ cells expanded preferentially. These T cells exerted cytolytic activity toward all Jeg3 cell lines. Conclusion: Our data suggest that, in spite of immunosuppressive mechanisms, proliferative and cytolytic T cell responses are induced by Jeg3 cells when classical HLA- and/or costimulatory signals are present on the cells. [source] Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer riskTHE PROSTATE, Issue 9 2007Bahar Mikhak Abstract BACKGROUND The vitamin D receptor (VDR) is required for actions of vitamin D. The binding of 1,25-dihydroxyvitamin D to the VDR on prostatic epithelial cells prompts the regulation of cancer-related genes. METHODS We conducted a nested case-control study in the Health Professionals Follow-up Study to investigate the role of the VDR Cdx2, Fok1, and Bsm1 gene polymorphisms and associated haplotypes and their interaction with plasma vitamin D metabolites in relation to prostate cancer (PC) risk. RESULTS No association was found between these SNPs or their associated haplotypes and all PC subtypes except that haplotype 2 (A-f-b) with Cdx2 A, Fok1 f, and Bsm1 b alleles and haplotype 3 (A-F-B) with Cdx2 A, Fok1 F and Bsm1 B alleles compared to the most common haplotype (A-F-b), were associated with reduced risk of aggressive PC (high stage or Gleason sum ,7; P,=,0.02), both with two alleles suspected of being low risk. Carriers of the variant Cdx2 A allele who were deficient in plasma 25-hydroxyvitamin D (,15 ng/ml) compared to non-carriers with normal 25-hydroxyvitamin D, had a lower risk of total and poorly differentiated PCs (Gleason sum ,7) (P for interaction,=,0.02 and 0.04, respectively). Plasma 1,25-dihydroxyvitamin D deficiency (,26 pg/ml) was associated with a threefold risk of poorly differentiated PC (P for interaction,=,0.01) when comparing carriers of the Cdx2 A allele to non-carriers with normal 1,25-dihydroxyvitamin D. CONCLUSION In this population of men, none of the VDR polymorphisms studied was associated with susceptibility to PC. Prostate 67: 911,923, 2007. © 2007 Wiley-Liss, Inc. [source] Novel polymorphisms in the bovine ,-lactoglobulin gene and their effects on , -lactoglobulin protein concentration in milkANIMAL GENETICS, Issue 2 2009N. A. Ganai Summary The aim of our study was to detect new polymorphisms in the bovine ,-lactoglobulin (,-LG) gene with significant effects on ,-LG protein concentration. Genomic DNA samples from 22 proven bulls were screened for polymorphisms in the coding and promoter regions of the ,-LG gene. In total, 50 polymorphisms were detected. Two single nucleotide polymorphisms (SNPs) (g.1772G>A and g.3054C>T) lead to amino acid changes and are the causal genetic polymorphisms of ,-LG protein variants A and B. Forty-two polymorphisms were in complete linkage disequilibrium (LD) with ,-LG protein variants A and B. Any of these 42 polymorphisms can be involved in the differential expression of the respective A and B alleles of the ,- LG gene. The eight polymorphisms not in complete LD with ,-LG protein variants A and B and the two polymorphisms causing the amino acid changes were genotyped in a set of 208 cows: 106 animals homozygous for ,-LG protein variant A and 102 animals homozygous for ,-LG protein variant B. Of these eight polymorphisms, six SNPs segregated only within the cows homozygous for ,-LG protein variant A and two SNPs segregated only within the cows homozygous for ,-LG protein variant B. One of the eight polymorphisms had a significant effect on ,-LG protein concentration. This SNP, g.-731G>A, segregated only within the 106 cows homozygous for ,-LG protein variant A. Within these cows, adjusted relative ,-LG protein concentration was reduced by 1.22% (w/w) in animals homozygous g.-731AA compared with animals homozygous g.-731GG. [source] Polymorphic Alu Insertions and their Associations with MHC Class I Alleles and Haplotypes in the Northeastern ThaisANNALS OF HUMAN GENETICS, Issue 4 2005D. S. Dunn Summary Polymorphic Alu insertions (POALINs) are known to contribute to the strong polymorphic nature of the Major Histocompatibility Complex (MHC). Previous population studies on MHC POALINs were limited to only Australian Caucasians and Japanese. Here, we report on the individual insertion frequency of the five POALINs within the MHC class I region, their HLA-A and -B associations, and the three and four locus alpha block POALIN haplotype frequencies in the Northeastern (NE) Thai population. Of the five POALINs, the lowest frequency was 0.018 for AluyHF and the highest frequency was 0.292 for AluyHJ and AluyHG. The strongest positive associations between the POALINs and HLA class I alleles was between AluyMICB and HLA-B*57, AluyHJ and HLA-A*24 and HLA-A*01, and AluyHG and HLA-A*02, supporting previous findings in Caucasians and Japanese. Single POALIN haplotypes were found more frequently than multiple POALIN haplotypes. However, of the seven different POALIN haplotypes within the MHC alpha block, there were only two significant differences between the NE Thais, Caucasians and Japanese. This study confirms that the MHC POALINs are in linkage disequilibrium with HLA-A and ,B alleles and that there are significant frequency differences for some of the POALINs when compared between NE Thai, Caucasians and Japanese. [source] Mannose-binding lectin gene polymorphism and resistance to therapy in women with recurrent vulvovaginal candidiasisBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2008GGG Donders Precis, Women with recurrent vulvovaginal candidiasis (RVC) due to a polymorphism in codon 54 of the MBL2 gene respond better to fluconazole maintenance therapy than do women with other underlying causes. Objective, To explain differences in response rates to maintenance therapy with fluconazole in women suffering from RVC by evaluating associations with a polymorphism in the gene coding for mannose-binding lectin (MBL). Design, Follow-up study, neted case-control group. Setting, Women attending vulvoginitis clinic for RVC. Population, Women participating in a multicentric study in Belgium with a degressive dose of fluconazole for RVC (the ReCiDiF trial) were divided into good responders, intermediate responders and nonresponders according to the number of relapses they experienced during therapy. From 109 of these women with adequate follow-up data, vaginal lavage with 2 ml of saline were performed at the moment of a proven acute attack at inclusion in the study, before maintenance treatment was started. A buccal swab was obtained from 55 age-matched women without a history of Candida infections, serving as a control group. Methods, Extracted DNA from buccal or vaginal cells was tested for codon 54 MBL2 gene polymorphism by polymerase chain reaction and endonuclease digestion. Main outcome measures, Frequency of MBL2 condon 54 allele B in women with optimal or poor response to maintenance therapy in composition with controls. Results, Women (n = 109) suffering from RVC were more likely to carry the variant MBL2 codon 54 allele B than control women (20 versus 6.6%, OR 3.4 [95% CI 1.3,8.2], P = 0.01). B alleles were present in 25% of the 36 women not suffering from any recurrence during the maintenance therapy with decreasing doses of fluconazole (OR 4.9 [95% CI 1.9,12.5], P = 0.0007 versus controls), in 20% of the 43 women with sporadic recurrences (OR 3.6 [95% CI 1.4,9.2], P = 0.007 versus controls) and in 15% of the 30 women who had to interrupt the treatment regimen due to frequent relapses (P = 0.097 versus controls). Conclusions, The MBL2 codon 54 gene polymorphism is more frequent in Belgian women suffering from RVC than in controls. The presence of the B allele is associated with a superior response to fluconazole maintenance therapy as compared with RVC patients without this polymorphism. We conclude that RVC due to deficient MBL production is more easily helped with antifungal medication than is RVC due to some other mechanism. [source] Distribution of HLA-A, B alleles and polymorphisms of TAP and LMP genes in Korean patients with atopic dermatitisCLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2001H. J. Lee Background Atopic dermatitis has been seen to result from multifactorial inheritance, with interaction between genetic and environmental factors. The genetic association may differ according to the ethnic backgrounds. Objective The purpose of this study was to investigate the genetic factors in Korean atopic dermatitis patients by studying the human leucocyte antigen (HLA) class I association and polymorphisms of transporters associated with antigen presentation (TAP) and low-molecular-weight polypeptide (LMP) genes. Methods HLA-A and B genotyping was performed in 53 atopic dermatitis patients and 184 healthy controls using the standard microlymphocytotoxicity technique. TAP1, TAP2, LMP2, and LMP7 gene polymorphisms were anaylzed using the polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP), PCR-amplification refractory mutation system (ARMS), and PCR-restriction fragment length polymorphism (RFLP). Results Allele frequency of HLA-A24 was significantly increased in patients with atopic dermatitis compared to controls (P < 0.05). HLA-B alleles showed no differences in distribution between patients and controls. Genotype, phenotype, and allele frequencies of TAP1 gene also revealed no differences in distribution between patients and controls. Analysis of TAP2 gene polymorphisms showed increased frequencies of the TAP2*C allele and TAP2*A/TAP2*C genotype in atopic dermatitis patients compared to controls (P < 0.05). Distribution of LMP2 and LMP7 gene polymorphisms was similar for patients and controls. Conclusion This study demonstrates an association of atopic dermatitis with HLA-A24 and TAP2*C alleles in Korean patients. Discrepancy with the previous reports might be related to different patient characteristics and ethnic variations. [source] DIFFERENTIAL PERFORMANCE AMONG LDH-B GENOTYPES IN RANA LESSONAE TADPOLESEVOLUTION, Issue 5 2000Hansjürg Hotz Abstract The European pool frog, Rana lessonae, is widely polymorphic for two common alleles (b, e) at the lactate dehydrogenase-B (LDH-B) locus. We compared fitness-related larval life-history traits among LDH-B genotypes, which originated from segregation in heterozygous parents, in an artificial pond experiment where tadpoles of R. lessonae from a Swiss population were raised together with tadpoles of the hemiclonal hybrid R. esculenta at two densities. In R. lessonae, LDH-B e/e homozygotes at each density had a higher proportion of metamorphs among survivors, reached metamorphosis earlier, and were heavier at metamorphosis than b/b homozygotes; b/e heterozygotes had intermediate values. That e/e individuals were superior to b/b in both time to and mass at metamorphosis is surprising because these two life-history traits are thought to reflect a performance trade-off; e/e genotypes apparently compensated for shorter time to metamorphosis by a higher growth rate. The two alleles showed the same performance ranking when combined in hybrids with a R. ridibunda allele: When R. esculenta from Swiss populations reared in the same ponds had received the e allele rather than the b allele from their R. lessonae parent, they reached metamorphosis earlier, but did not differ in mass at metamorphosis. The degree of linkage disequilibrium in the source population of the eight R. lessonae used as parents of the R. lessonae tadpoles is unknown, so we cannot exclude the possibility that the performance differences are caused by some anonymous tightly linked gene, rather than the LDH-B locus, that constitutes the genomically localized target of natural selection. A causal involvement of LDH-B is plausible, nevertheless, because this enzyme takes part in the central energy-metabolizing processes and has been reported to underlie fitness differences in other animals; also, differential performance of LDH-B genotypes has been observed in R. lessonae larvae from another population. The present results suggest strong directional selection for allele e; the sum of available data, including an independent laboratory experiment, suggests that partial environment-dependent overdominance combined with balancing selection favoring e/e homozygotes under some and b/b homozygotes under other conditions may be partially responsible for the broad maintenance of the LDH-B polymorphism in R. lessonae. [source] Validation of a real-time PCR for the quantitative estimation of a G143A mutation in the cytochrome bc1 gene of Pyrenophora teresPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2007Arash Kianianmomeni Abstract A single nucleotide polymorphism (SNP) in the cytochrome b gene confers resistance to strobilurin fungicides for several fungal pathogens. Therefore, on the basis of a change at amino acid position 143 from glycine to alanine, a real-time PCR assay was established for the quantitative detection of the analogous SNP in the cytochrome b sequence of Pyrenophora teres Drechsler, which causes barley net blotch. Allelic discrimination was achieved by using allele specific primers with artificially mismatched nucleic acid bases and minor groove binding probes. Validation parameters for the lower limits of the working range, namely limits of detection (LOD) and limits of quantification (LOQ), were statistically determined by the variance of calibration data, as well as by the variance of the 100% non-strobilurin-resistant allele DNA sample (blank values). It was found that the detection was limited by the variance of blank values (five in 801 458 copies; 0.0006%), whereas the quantification was limited by the variance of calibration data (37 in 801 458 copies; 0.0046%). The real-time PCR assay was finally used to monitor strobilurin-resistant cytochrome b alleles in barley net blotch field samples, which were already classified in in vivo biotests to be fully sensitive to strobilurins. All signals for strobilurin-resistant cytochrome b alleles were below the LOD, and therefore the results are in total agreement with the phenotypes revealed by biotests. Copyright © 2006 Society of Chemical Industry [source] Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer riskTHE PROSTATE, Issue 9 2007Bahar Mikhak Abstract BACKGROUND The vitamin D receptor (VDR) is required for actions of vitamin D. The binding of 1,25-dihydroxyvitamin D to the VDR on prostatic epithelial cells prompts the regulation of cancer-related genes. METHODS We conducted a nested case-control study in the Health Professionals Follow-up Study to investigate the role of the VDR Cdx2, Fok1, and Bsm1 gene polymorphisms and associated haplotypes and their interaction with plasma vitamin D metabolites in relation to prostate cancer (PC) risk. RESULTS No association was found between these SNPs or their associated haplotypes and all PC subtypes except that haplotype 2 (A-f-b) with Cdx2 A, Fok1 f, and Bsm1 b alleles and haplotype 3 (A-F-B) with Cdx2 A, Fok1 F and Bsm1 B alleles compared to the most common haplotype (A-F-b), were associated with reduced risk of aggressive PC (high stage or Gleason sum ,7; P,=,0.02), both with two alleles suspected of being low risk. Carriers of the variant Cdx2 A allele who were deficient in plasma 25-hydroxyvitamin D (,15 ng/ml) compared to non-carriers with normal 25-hydroxyvitamin D, had a lower risk of total and poorly differentiated PCs (Gleason sum ,7) (P for interaction,=,0.02 and 0.04, respectively). Plasma 1,25-dihydroxyvitamin D deficiency (,26 pg/ml) was associated with a threefold risk of poorly differentiated PC (P for interaction,=,0.01) when comparing carriers of the Cdx2 A allele to non-carriers with normal 1,25-dihydroxyvitamin D. CONCLUSION In this population of men, none of the VDR polymorphisms studied was associated with susceptibility to PC. Prostate 67: 911,923, 2007. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||