Codominant Alleles Research Articles

Association of Acid Phosphatase‐1 (ACP1) Gene Polymorphism with MAI infection.

Human acid phosphatases are normally found at low concentrations. However, pronounced changes in their synthesis occur in particular diseases, where unusually high or low enzyme expression is seen as part of the pathophysiological process. Acid Phosphatase locus 1 (ACP1) is a polymorphic enzyme controlled by a locus on chromosome 2 with three common codominant alleles: *A, *B, and *C. ACP1 shows two major isoforms, F and S. Genetic polymorphisms could contribute to natural resistance or susceptibility to the disease. Genetic screens in humans link polymorphisms in or near the ACP1 locus to a variety of inflammatory diseases including allergy and asthma. ACP1 is involved in activation, adhesion, and differentiation of T cells. Though few studies have shown the presence of ACP in human tissues, no studies have been reported linking ACP1 gene polymorphism to susceptibility to infections. In this study we investigate the role of ACP1 gene polymorphism in patients infected with Mycobacterium avium and normal healthy subjects. Mycobacterium avium complex (MAC) consists of two species: M avium and M intracellulare; because these species are difficult to differentiate, they are also collectively referred to as Mycobacterium avium‐intracellulare (MAI). Mycobacterium avium is an environmental microorganism which also exists in multiple hosts, including humans. M. avium can invade and replicate in immunocompromised hosts and also enhances permissiveness for HIV‐1 infection. DNA was extracted from blood and PCR‐RFLP method was used to detect ACP‐1 gene polymorphism. Our study showed high frequency of ACP AB haplotype (44%) in patients with infection than in individuals with no infection (24.8%) showing a significant association with infection (p<0.006). This is the first study to show an association of ACP1 gene with MAI. Our study highlights the role of gene/s polymorphism and their possible association with infection.Support or Funding InformationEisenhower Medical Center Research funds for Infectious disease.,

Prediction of MNS Blood Group Antigens Using Next Generation Sequencing

▪Background The MNS blood group system is second in diversity only to the RH blood group system, with 46 described antigens. MNS system antigens are carried on glycophorins GPA and GPB that are products of the GYPA and GYPB genes, respectively. GYPA and GYPB are homologous paralogs which lie adjacent to each other on chromosome 4 in tandem with a third GYP paralog, GYPE. Current DNA-based testing methods for predicting MNS can be confounded by all types of genetic variation at the GYP locus, particularly in individuals of non-European ancestry. We sought to develop a next generation sequencing (NGS) approach for the systematic characterization of the GYP locus to accurately predict the common M/N and S/s blood group antigens and simultaneously identify other clinically relevant GYP DNA variants.Study Methods A total of 1139 samples were DNA sequenced; 1135 were from a previous study of blood donors self-identified to be of Asian American or Native American descent, and were 4 WHO reference DNAs (NIBSC). Blood donors had been tested for M and N by serology and for M/N and S/s using a single nucleotide variant (SNV) blood group genotyping platform (Bioarray). Samples were selected to enrich for MNS serology-SNV discrepancies or indeterminate results.BloodSeq is a NGS targeted panel that includes capture of 97.4kb over 3 genomic regions including the exons, pseudo-exons, introns, and proximal intergenic regions of GYPA, GYPB, and GYPE. This custom capture was used to generate Illumina, paired-end 100 bp DNA sequence reads. Raw sequence data was aligned to the human reference genome (hg19) and SNVs assessed using standard calling methods (GATK HaplotypeCaller). To predict MNS blood group system antigens, we determined variants which identified ISBT alleles; M/N antigens were defined as codominant alleles with multiple variant sites present in GYPA exon 2, while S/s antigens were defined by GYPB c.143T>C (p.Thr48Met) and 2 known GYPB silencing SNVs. Other DNA variants were cross-referenced with ISBT to predict associated blood group antigens.Results In a preliminary analyses, standard DNA variant calling methods predicted S/s (GYPB) SNVs accurately. However, alleles with M (GYPA) blood group variants exhibited a low call rate. Visualization of aligned reads indicated alleles corresponding to the M blood group sequence align poorly to the reference GYPA sequence. We traced the origin of these poor quality alignments to the presence of a region in GYPE with high sequence homology to the GYPA M allele. Notably, in the reference genome the GYPA gene has DNA variants indicative of theN genotype. With this knowledge, we developed a new approach which considers alignments of all 3 genes (GYPA, GYPB, GYPE) to predict M/N and S/s blood group antigens. Applying this method, BloodSeq predicted M with high concordance with serology (99.2%) and SNV genotype (99.6%), similar to the SNV genotype-serology concordance for M (98.9%). BloodSeq also predicted S/s in high concordance with the SNV predicted genotype (99.4% and 99.8%, respectively for S and s). Prediction of N by both BloodSeq and SNV genotype were similar to each other (99.6%) but exhibited lower accuracy (86.1% and 85.6%, respectively) when compared to serology. Interestingly, most (90%) of the N discrepancies were genetic prediction of absent N antigen but a positive N result by serology. We suspect these discrepancies result from cross-reactivity of reagent antibodies with "N" (an N-like antigen encoded by GYPB), which would require additional DNA sequence curation, or other underlying genetic variation. Additionally, 9 GYPA and GYPB variants indicative of other named ISBT alleles were detected, as well as a novel predicted frameshift variant in GYPA.Conclusion Our results demonstrate that a targeted NGS approach followed by an analysis pipeline customized for the GYP locus can simultaneously predict M/N and S/s blood groups and detect other GYP variants of known clinical significance. We propose that use of GYP locus-specific DNA sequence analysis strategies, such as addition of alternative reference sequences, should allow for automated and reliable classification of the M/N, S/s, and other variants in the MNS blood group system using next generation DNA sequencing. This work provides the foundation for a DNA-based, high resolution blood-typing method for the detection of clinically relevant MNS blood group system genetic variation. DisclosuresJohnsen:CSL Behring: Consultancy; Octapharma: Consultancy.

Evaluation of genetic diversity of sweet potato [Ipomoea batatas (L.) Lam.] on different ploidy levels applying two capillary platforms

ABSTRACTThe genetic composition of sweet potato [Ipomoea batatas (L.) Lam.] (2n = 6x = 90) is reflected in different levels of genetic variation. The main objective of the present study was a comparison of genetic diversity parameters of different ploidy levels (2n, 4n, and 6n codominant allele determination), analyzed on two high-resolution capillary platforms. Fragment analysis was performed by applying SSR markers on a 3130XL Genetic Analyzer (ABI 3130) and QIAxcel Advanced System (QX). A high level of expected heterozygosity (He) as a measure of genetic diversity was observed for both ABI3130 (0.731) and QX (0.679). Molecular variance was 17% for ABI3130 and 10% for QX. Comparison between genetic distance matrices based on allele lengths showed a moderate Mantel correlation coefficient (rxy = 0.557) between ABI3130 and QX. Global cluster analysis using the Bayesian approach distributed the observed genotypes into two clusters on both capillary platforms. Our results show that the two high-resolution capillary electrophoreses for codominant data on 2n, 4n, and 6n levels are applicable in genetic diversity studies but their efficiency depends on in-resolution expectations, financial resources, available time, and the equipment of the laboratory.

The genetic basis of discrete and quantitative colour variation in the polymorphic lizard, Ctenophorus decresii.

BackgroundColour polymorphic species provide invaluable insight into processes that generate and maintain intra-specific variation. Despite an increasing understanding of the genetic basis of discrete morphs, sources of colour variation within morphs remain poorly understood. Here we use the polymorphic tawny dragon lizard Ctenophorus decresii to test simple Mendelian models for the inheritance of discrete morphs, and to investigate the genetic basis of continuous variation among individuals across morphs. Males of this species express either orange, yellow, orange surrounded by yellow, or grey throats. Although four discrete morphs are recognised, the extent of orange and yellow varies greatly. We artificially elevated testosterone in F0 females and F1 juveniles to induce them to express the male throat colour polymorphism, and quantified colour variation across the pedigree.ResultsInheritance of discrete morphs in C. decresii best fit a model whereby two autosomal loci with complete dominance respectively determine the presence of orange and yellow. However, a single locus model with three co-dominant alleles for orange, yellow and grey could not be definitively rejected. Additionally, quantitative expression of the proportion of orange and yellow on the throat was strongly heritable (orange: h2 = 0.84 ± 0.14; yellow: h2 = 0.67 ± 0.19), with some evidence for covariance between the two.ConclusionsOur study supports the theoretical prediction that polymorphism should be governed by few genes of major effect, but implies broader genetic influence on variation in constituent morph traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0757-2) contains supplementary material, which is available to authorized users.

The art of attrition: development of robust oat microsatellites

AbstractMicrosatellite or simple sequence repeat (SSR) markers are important tools for genetic analyses, especially those targeting diversity. The primary objective of this study was to develop robust oat‐based microsatellite markers from newly enriched genomic libraries to expand on a relatively small existing oat SSR toolbox. Microsatellite motifs characterized by (CA/GT), (AAT/TTA), (ATG/TAC) and (CATC/GTAG) repeats were targeted for enrichment. Preliminary screening showed that 90% of clones from the (CA/GT) and 79% of the clones from the (ATG/TAC) libraries contained repeats, while < 11% of the clones from (AAT/TTA) and (CATC/GTAG) libraries contained repeats. Subsequent sequencing of 1536 clones from the (CA/GT) and (ATG/TAC) libraries resulted in 539 and 578 SSRs for which primers were designed, respectively. A total of 246 SSRs were polymorphic across 11 oat lines. One hundred and twenty‐five of the markers produced highly reproducible assays that interrogated 369 alleles at 193 loci. Of these, 79 robust assays interrogated 146 codominant alleles. These markers will be useful for a wide range of genetic analyses in oat including assessment of diversity and marker‐assisted breeding.

Duffy blood group antigens: structure, serological properties and function

Duffy (Fy) blood group antigens are located on seven-transmembrane glycoprotein expressed on erythrocytes and endothelial cells, which acts as atypical chemokine receptor (ACKR1) and malarial receptor. The biological role of the Duffy glycoprotein has not been explained yet. It is suggested that Duffy protein modulate the intensity of the inflammatory response. The Duffy blood group system consists of two major antigens, Fy(a) and Fy(b), encoded by two codominant alleles designated FY*A and FY*B which differ by a single nucleotide polymorphism (SNP) at position 125G>A of the FY gene that results in Gly42Asp amino acid change in the Fy(a) and Fy(b) antigens, respectively. The presence of antigen Fy(a) and/or Fy(b) on the erythrocytes determine three Duffy-positive phenotypes: Fy(a+b-), Fy(a-b+) and Fy(a+b+), identified in Caucasian population. The Duffy-negative phenotype Fy(a-b-), frequent in Africans, but very rare in Caucasians, is defined by the homozygous state of FY*B-33 alleles. The FY*B-33 allele is associated with a SNP -33T>C in the promoter region of the FY gene, which suppresses erythroid expression of this gene without affecting its expression in other tissues. The FY*X allele, found in Caucasians, is correlated with weak expression of Fy(b) antigen. Fy(x) antigen differs from the native Fy(b) by the Arg89Cys and Ala100Thr amino acid substitutions due to SNPs: 265C>T and 298G>A in FY*B allele. The frequency of the FY alleles shows marked geographic disparities, the FY*B-33 allele is predominant in Africans, the FY*B in Caucasians, while the FY*A allele is dominant in Asians and it is the most prevalent allele globally.

Gene duplication and divergence affecting drug content in Cannabis sativa.

Cannabis sativa is an economically important source of durable fibers, nutritious seeds, andpsychoactive drugs but few economic plants are so poorly understood genetically. Marijuana and hemp were crossed to evaluate competing models of cannabinoid inheritance and to explain the predominance of tetrahydrocannabinolic acid (THCA) in marijuana compared with cannabidiolic acid (CBDA) in hemp. Individuals in the resulting F2 population were assessed for differential expression of cannabinoid synthase genes and were used in linkage mapping. Genetic markers associated with divergent cannabinoid phenotypes were identified. Although phenotypic segregation and a major quantitative trait locus (QTL) for the THCA/CBDA ratio were consistent with a simple model of codominant alleles at a single locus, the diversity of THCA and CBDA synthase sequences observed in the mapping population, the position of enzyme coding loci on the map, and patterns of expression suggest multiple linked loci. Phylogenetic analysis further suggests a history of duplication and divergence affecting drug content. Marijuana is distinguished from hemp by a nonfunctional CBDA synthase that appears to have been positively selected to enhance psychoactivity. An unlinked QTL for cannabinoid quantity may also have played a role in the recent escalation of drug potency.

Genetic identity of common buckwheat (Fagopyrum esculentum Moench) landraces locally cultivated in the Alps

The conservation of landraces in Europe is challenging because very often they have already disappeared or cannot be properly identified, which in turn prevents any possibility for their utilization. This work deals with the collection of molecular and historical data to identify and study the original landraces of common buckwheat (Fagopyrum esculentum Moench), locally cultivated in Northern Italy (Valtellina) and to date surviving among other commercial varieties, recently introduced in the same areas of the Alps. As plant materials of F. esculentum, we analyzed a number of Italian accessions along with two foreign accessions from Poland and Nepal, for a total of 174 individuals. Molecular investigations were based on a set of eight nuclear SSR marker loci. The mean observed heterozygosity over all accessions was equal to Ho = 0.466, being significantly lower than the expected heterozygosity (He = 0.764). A major finding was the recognition of a marked inbreeding rate (Fit = 0.387) and a reduced fixation index (Fst = 0.061), indicating that most genetic variation is found within populations. A significant overall gene flow among accessions was found (Nm = 3.846). Results indicated that only two of the examined accessions, the so-called “Nustran” and “Curunin”, could be considered, authentic Valtellina landraces. On the basis of results, we successfully developed a multi-locus marker system and identified a number of co-dominant marker alleles suitable for genetic traceability and authenticity certification of a “Nustran” and a “Curunin” autochthonous landraces of Valtellina and its food derivatives (i.e., Pizzoccheri, Polenta taragna).

Association of ABCB1/MDR1 polymorphisms in patients with glucocorticoid-induced osteonecrosis of the femoral head: Evidence for a meta-analysis

PurposeGlucocorticoid-induced osteonecrosis of the femoral head (GC-induced ONFH) is a rebarbative disease affecting people from all ages, especially young adults, and often leads to severe joint pain and limitations on physical activity. Numerous studies have reported that ABCB1 polymorphisms are associated with GC-induced ONFH, but the results are inconclusive, partially because the sample size of published studies is relatively small. Therefore, we performed a meta-analysis including seven case–control studies to estimate such association. MethodsPublished literature from Medline, Embase, and CNKI were searched for eligible publications. Pooled odds ratio (OR) together with their 95% confidence (CI) was calculated using a fixed effect model or random effect model. The meta-analysis was performed in accordance to PRISMA Statement Criteria. ResultsThe ABCB1 3435T allele reduces the GC-induced ONFH risk based on the evidence from the co-dominant model (CT vs. CC, OR=0.73, 95% CI: 0.53–1.00; TT vs. CC, OR=0.43, 95% CI: 0.26–0.69), dominant model (CT+TT vs. CC, OR=0.64, 95% CI: 0.48–0.87), allele contract model, (T vs. C, OR=0.68, 95% CI: 0.54–0.84), and recessive model (TT vs. CC+CT, OR=0.52, 95% CI: 0.34–0.81). Similarly, the ABCB1 2677T/A allele reduce the GC-induced ONFH risk based on the evidence from the co-dominant model (GT/A vs. GG, OR=0.66, 95% CI: 0.45–0.96; T/AT/A vs. GG, OR=0.52, 95% CI: 0.34–0.82), dominant model (GT/A+T/AT/A vs. GG, OR=0.61, 95% CI: 0.43–0.87), and allele contract model (T/A vs. G, OR=0.73, 95% CI: 0.58–0.90). ConclusionsThe meta-analysis revealed that 3435T allele and ABCB1 2677T/A allele may decrease the risks of GC-induced ONFH.

Association of ACP1 gene polymorphisms and coronary artery disease in northeast Chinese population.

Coronary artery disease (CAD) is the major cause of death in most countries including China (He et al. 2005). A number of susceptible variants of candidate genes have been recognized as genetic risk factors that are associated with pathogenesis of coronary heart disease (Wu et al. 2001; Achour et al. 2011; Zhou et al. 2011). Recently, Banci et al. (2009) have reported acid phosphatase 1 (ACP1) gene *C allele as a risk factor for CAD in Caucasian (OR= 3.188). Here, we show that the genotype GA of rs79716074 (ACP1 gene, exon 6) is associated with decreased risk of CAD in northeast Chinese population especially in females. The ACP1 gene is the only member of class II cysteinebased protein tyrosine phophatase (PTP) family in human and encodes the low molecular weight PTP (LMW-PTP), a group of 18-kDa proteins widely expressed in many tissues. LMW-PTP is involved in the regulation of important physiological processes including stress resistance and synthesis of the polysaccharide capsule, etc. (Souza et al. 2009). There are three common codominant alleles of ACP1: ACP1*A, ACP1*B and ACP1*C. which contains single base substitutions located at specific sites. The ACP1*C allele differs from ACP1*A and ACP1*B alleles at rs11553742, while ACP1*A and ACP1*B alleles differ in an A–G transition at rs79716074. Previous studies reported that ACP1 gene polymorphisms may be important pathogenic factors of immune dysregulation such as rheumatoid arthritis, systemic lupus erythematosis process, endometriosis and allergy (Ammendola et al. 2008, Teruel et al. 2011, 2012).

Multidisciplinary approach to identify gene-environment interplay triggering autism

Multidisciplinary approach to identify gene-environment interplay triggering autism

Abstract 1858: Genetic variations in acid phosphatase 1 (ACP 1) gene and cancer risk

Abstract BACKGROUND: Human acid phosphatases are normally found in low concentrations, but pronounced changes in their synthesis occur in particular diseases where unusually high or low enzyme expression is seen as part of the pathophysiological process,suggesting the clinical relevance of ACP as a disease marker. Acid Phosphatase 1 (ACP1) is considered to play a key role as a regulator of signaling pathways in receptor-stimulated immune cells and is known to be widely expressed and endowed with metabolic and proliferative activity. We hypothesized ACP1 could serve as a predictive marker in identifying cancer patients at an earlier stage, especially when disease is treatable. Acid phosphatase enzymes is generally correlated with the 3 co-dominant alleles A, B & C. This is the first study screening two ACP1 gene polymorphisms and ACP gene expressions in different cancer types. In this study, we exploit a novel connection of enzymatic activity in correlations to these two ACP1 polymorphisms and with more specific quantification of acid phosphatase in tumor tissues in primary and metastatic cancer patients. METHODS: All study subjects were non-Hispanic Caucasians. The study sample was comprised of 661 cancer patients (221 breast; 121 prostate;137 malignant melanoma;196 other cancers) and 827 healthy controls. DNA & RNA was isolated from all cancer patients & controls using standard procedure.PCR-RFLP method was used. ACP1 alleles (i.e., ACP1*A, ACP1*B, and ACP1*C) were determined with 2 of the selected SNPs: rs11553742 (C>T) is a synonymous polymorphism located in the codon 44 (exon 3) and rs7576247 (A/G) encodes an amino acid change in the codon 105 (exon 6) from arginine, present in ACP1*A allele, to glutamine in ACP1*B and *C alleles. Genotype and haplotype analysis was done using PASW 18 (SPSS IBM). qPCR is performed in tumor tissues and comparisons were made among cancer types and also in correlation with the haplotype based enzyme activity. RESULTS: A very significant association of ACP haplotypes AA & AB with cancers is observed (p<0.00001). Further analysis of these haplotypes in cancer types controlling for age and sex showed significant association mainly with Melanoma (p<0.0001); prostate ca (p<0.002); breast ca (p<0.013) and all other cancers (p< 0.002). Primary cases showed low activity while the metastatic cases showed high activity (> 2fold). CONCLUSIONS:The enzymatic activity from gene combination correlates with the gene expression data. The primary cancer cases showed a low expression. Our data also shows an over expression of ACP1(>2 fold) in metastatic cases as compared to the primary cases. This data supports the previous report on alkaline phosphatases (APs) catalyse and facilitate important physiological changes within cells and their expression is altered in many disease processes. It is clearly evident from this study that the ACP1 gene can be a critical marker in screening patients who are deemed low to high risk for cancer and metastasis. Citation Format: Radhika G. Andavolu, Jean-Luc Cardenas, Svetlana Rubakovic, Sina J. Torabi, Patrick Herling, James MacMurray, Murthy VS Andavolu. Genetic variations in acid phosphatase 1 (ACP 1) gene and cancer risk. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1858. doi:10.1158/1538-7445.AM2014-1858

Inheritance of Seed Protein Subunits of Common Buckwheat (Fagopyrum esculentum Moench) Cultivar Sobano and Its Homostylous Wild Type

The seed protein subunits of common buckwheat Sobano (Fagopyrum esculentum) and its homostylous wild type “HOMO” (F.esculentum var. homotropicum) were studied by means of SDS-PAGE analysis. The results showed that there are 33 bands of seed protein subunits in Sobano and 31 bands in HOMO. Most of them were found in the cotyledon and a few in the endosperm. There are nine subunits in Sobano seeds and ten subunits in HOMO. The inheritance analysis of the seed protein subunits in progenies of hybrids between Sobano and HOMO showed that there are four pairs of protein subunits controlled by a single co-dominant allele. The genetic analysis of morphological characters indicated that homostyly, shattering and acute achenes are controlled by different dominant single genes. The shattering gene has a linkage to the homostyly locus in a rate of 7.81% and to the allele PS44/PS42.9 in a rate of 22.54%.

A PCR marker Linked to a THCA synthase Polymorphism is a Reliable Tool to Discriminate Potentially THC‐Rich Plants of Cannabis sativa L.

Neither absolute THC content nor morphology allows the unequivocal discrimination of fiber cultivars and drug strains of Cannabis sativa L. unequivocally. However, the CBD/THC ratio remains constant throughout the plant's life cycle, is independent of environmental factors, and considered to be controlled by a single locus (B) with two codominant alleles (B(T) and B(D)). The homozygous B(T)/B(T) genotype underlies the THC-predominant phenotype, B(D)/B(D) is CBD predominant, and an intermediate phenotype is induced by the heterozygous state (B(T)/B(D)). Using PCR-based markers in two segregating populations, we proved that the THCA synthase gene represents the postulated B locus and that specific sequence polymorphisms are absolutely linked either to the THC-predominant or the THC-intermediate chemotype. The absolute linkage provides an excellent reliability of the marker signal in forensic casework. For validation, the species-specific marker system was applied to a large number of casework samples and fiber hemp cultivars.

Biochemical characterization of indigenous Fulani and Yoruba ecotypes chicken of Nigeria

The study was carried out to characterize two indigenous chickens of Nigeria using protein markers; haemolglobin (HB) and carbonic anhydrase (CA). Separation of the two proteins was achieved by cellulose acetate electrophoresis and direct gene counting method was employed to interpret the result. Palentological statistics was used to generate dendrogram that measured genetic similarity within and between each of the population studied. HB was interpreted into three phenotypes: AA, AB and BB which were genetically controlled two codominant alleles HBA and HBB. Allele frequencies of HBA and HBB in Yoruba ecotype chicken were 0.34 and 0.66, respectively, while those of Fulani ecotype were 0.28 and 0.72, respectively. CA was also interpreted into three phenotypes (FF, FS and SS) which are genetically controlled by two codominant alleles CAF and CAS; their respective allele frequencies were 0.33 and 0.67 in Yoruba ecotype chicken and 0.24 and 0.76 in Fulani ecotype chicken. Genetic similarity within ecotype indicated 60% in Fulani, 80% in Yoruba and 40% between Yoruba and Fulani at HB locus while at CA locus, genetic similarity was 69% in Fulani ecotype, 50% in Yoruba ecotype and 42% between Yoruba and Fulani ecotype. Cavalli-Sforza genetic distance between the two Ecotypes was 2.1x10-2. Conclusively, the two populations were genetically related and further studies should focus on other protein markers and at molecular level. Key words: Ecotype, protein marker, genetic distance and selection.

Polymorphism of the complement receptor 1 gene correlates with the hematologic response to eculizumab in patients with paroxysmal nocturnal hemoglobinuria

Complement blockade by eculizumab is clinically effective in hemolytic paroxysmal nocturnal hemoglobinuria. However, the response is variable and some patients remain dependent on red blood cell transfusions. In 72 patients with hemolytic paroxysmal nocturnal hemoglobinuria on eculizumab we tested the hypothesis that response may depend on genetic polymorphisms of complement-related genes. We found no correlation between the complement component C3 genotypes and the need for blood transfusions. On the other hand, we found a significant correlation with the HindIII polymorphism of a complement regulatory gene, the complement receptor 1 (CR1) gene. At this locus two co-dominant alleles are known, of which H (common) is associated with high expression, whereas L (rare) is associated with low expression of CR1 on red blood cells. Patients who still needed blood transfusion on eculizumab accounted for 18% of the H/H homozygotes, 33% of the H/L heterozygotes and 68% of the L/L homozygotes (P=0.016). Thus, patients with paroxysmal nocturnal hemoglobinuria who have the L/L genotype are seven times more likely to be sub-optimal responders to eculizumab. Both in vitro and in vivo we found that the CR1 HindIII genotype correlates with the abundance of paroxysmal nocturnal hemoglobinuria red cells that have bound C3, and with the kinetics of C3 binding. These results are consistent with the notion that by affecting C3 binding the CR1 genotype influences the response to eculizumab treatment, and this emerges as a novel example of pharmacogenetics.

Role of a gamma‐aminobutryic acid (GABA) receptor mutation in the evolution and spread of Diabrotica virgifera virgifera resistance to cyclodiene insecticides

The western corn rootworm, Diabrotica virgifera virgifera, is a damaging pest of cultivated corn that was controlled by applications of cyclodiene insecticides from the late 1940s until resistance evolved ∼10 years later. Range expansion from the western plains into eastern USA coincides with resistance development. An alanine to serine amino acid substitution within the Rdl subunit of the gamma-aminobutyric acid (GABA) receptor confers resistance to cyclodiene insecticides in many species. We found that the non-synonymous single nucleotide polymorphism (SNP) G/T at the GABA receptor cDNA position 838 (G/T(838)) of D. v. virgifera resulted in the alanine to serine change, and the codominant SNP allele T(838) was genetically linked to survival of beetles in aldrin bioassays. A phenotypic gradient of decreasing susceptibility from west to east was correlated with higher frequencies of the resistance-conferring T(838) allele in the eastern-most populations. This pattern exists in opposition to perceived selective pressures since the more eastern and most resistant populations probably experienced reduced exposure. The reasons for the observed distribution are uncertain, but historical records of the range expansion combined with the distribution of susceptible and resistant phenotypes and genotypes provide an opportunity to better understand factors affecting the species' range expansion.

Effects of COMT genotype on sensory gating and its modulation by nicotine: Differences in low and high P50 suppressors

Elevated smoking rates seen in schizophrenia populations may be an attempt to correct neuropathologies associated with deficient nicotinic acetylcholine receptors and/or dopaminergic systems using exogenous nicotine. However, nicotine’s effects on cognitive processing and sensory gating have been shown to be baseline-dependent. Evidence of a restorative effect on sensory gating deficits by nicotine-like agonists has been demonstrated, however, its underlying mechanisms in the context of dopamine dysregulation are unclear. Catechol-O-methyltransferase (COMT), a key dopamine regulator in the brain, contains a co-dominant allele in which a valine-to-methionine substitution causes variations in enzymatic activity leading to reduced synaptic dopamine levels in the Val/Val genotype. Using a randomized, double-blind, placebo-controlled design with 57 non-smokers, this study examined the effects of COMT genotype on sensory gating and its modulation by nicotine in low vs. high suppressors. The results were consistent with the hypothesis that increased dopamine resulting from nicotine stimulation or Met allelic activity would benefit gating in low suppressors and impair gating in high suppressors, and that this gating improvement with nicotine would be more evident in Val carriers who were low suppressors, while the gating impairment would be more evident in Met carriers who were high suppressors. These findings reaffirm the importance of baseline-dependency and suggest a subtle relationship between COMT genotype and baseline-stratified levels of sensory gating, which may help to explain the variability of cognitive abilities in schizophrenia populations.

Haemoglobin Polymorphism in Red Sokoto Goats of Nigeria.

This study describes the genetic structure from the Hb locus in goats of the Red Sokoto type. The haemotypification of the individuals at the Hb locus was achieved by Cellulose acetate electrophoresis. The haemoglobin polymorphism in the Red Sokoto goat was identified in the electrophoretic field of three migration zones: the fast haemoglobin named HbA type, the intermediate migration labelled HbAHbB type and the slow haemoglobin designated HbB type. These phenotypes were determined by the two co-dominant alleles, HbA and HbB. The two alleles control three haemoglobin genotypes: two homozygotes, HbAHbA and HbBHbB, and one heterozygote, HbAHbB. The allele HbA had a higher frequency (60.4%) than the allele HbB (39.6%). The HbAHbB heterozygotes had a higher incidence in the population (64.15%) in comparison with the other two homozygous genotypes; the HbAHbA had a middling frequency (28.30%) and HbBHbB had the least occurrence (7.55%). The observed haemoglobin homozygotness (35.8%) was less than the haemoglobin heterozygotness (64.2%) in the current study. This indicates that environmental conditions, selection system or breeding methods has disturbed the Hardy-Weinberg genetic equilibrium at the Hb locus level in the population of Red Sokoto goats.

Saponin polymorphism in the Korean wild soybean (Glycine soja Sieb. and Zucc.)

AbstractSeed saponin composition of 3025 wild soybean (Glycine soja Sieb. and Zucc.) accessions collected from nine regions of Korea was analysed by thin‐layer chromatography to determine its polymorphic variation and geographical distribution and find mutants in saponin components. The saponin composition of seed hypocotyls was primarily divided into seven phenotypes, designated as Aa, Ab, AaBc, AbBc, Aa+α, AaBc+α and AbBc+α. The predominant phenotypes were AaBc (55%), Aa (33%), AaBc+α (7.5%) and Aa+α (3.3%). The frequencies of Ab, AbBc and AbBc+α were very low (0.3‐0.5%). Codominant alleles Sg‐1a and Sg‐1b and dominant allele Sg‐4 occupied 98.6, 1.1 and 63.3%, respectively. Alleles Sg‐3 and Sg‐5 were found to be dominant in all the analysed accessions except the mutants. Three accessions were discovered as mutants via LC‐PDA/MS/MS. The accession CWS0115 did not produce saponin Aa and Ax, CWS2133 did not produce saponin Aa and Ab and CWS5095 did not produce any group A saponins. These newly determined mutants might be utilized in producing a new soybean variety with good taste as well as in biosynthetic studies.