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PubMed2004

Polymorphisms in interleukin-1 beta and Interleukin-1 receptor antagonist genes are associated with kidney failure in Korean patients with type 2 diabetes mellitus.

BACKGROUND/AIM: Cytokines play an important role in the pathogenesis of kidney diseases. The aim of the study was to investigate the impact of interleukin (IL)-1 cluster genes on diabetic nephropathy in Korean patients with type 2 diabetes mellitus (DM). METHODS: We investigated -511 C/T polymorphism of IL-1 beta and tandem repeat polymorphism in intron 2 of IL-1 receptor antagonist in type 2 DM patients with end-stage kidney failure as compared with patients without nephropathy. RESULTS: The IL1B2 allele was found more frequently in patients with kidney failure than in controls (57.4 vs. 46.1%, p < 0.05). An excessive homozygous carriage of IL1B2 was found in patients with kidney failure when compared with controls (30.5 vs. 18.3%, p < 0.05). The allelic frequency of IL1RN*2 was also higher in cases than in controls without nephropathy (8.4 vs. 2.8 %, p < 0.05). The carriage rate of IL1RN*2 was significantly associated with an increased risk of kidney failure (15.8 vs. 5.6%; OR 3.19, 95% CI 1.24-8.17). The risk of kidney failure was highest in those carrying both IL1RN*2 and IL1B2 (OR 3.90, 95% CI 1.34-11.40). CONCLUSION: IL1B2 and IL1RN*2 genotypes of the IL-1 cluster genes are associated with diabetic nephropathy in Korean patients with type 2 DM.

Aged↗

PubMed2005

A C1173T dimorphism in the VKORC1 gene determines coumarin sensitivity and bleeding risk.

BACKGROUND: A C1173T polymorphism in intron 1 of the VKORC1 gene has been claimed to determine the interindividual variability in the response to vitamin K antagonist therapy (VKA), but it is unknown whether it also influences bleeding risk. We aimed to confirm the relationship between C1173T status and phenprocoumon or acenocoumarol use, and to examine the risk of severe bleeding for the various genotypes. METHODS AND FINDINGS: We studied this in a case-control study of 110 patients who bled during VKA therapy and 220 control patients free of bleeding under the same therapy. To achieve the same target INR, CT genotype and TT genotype control patients required less phenprocoumon (CC genotype 2.9 mg/d [95% confidence interval (CI): 2.6-3.2], CT genotype 2.6 mg/d [95% CI: 2.1-3.1], TT genotype 1.4 mg/d [95 % CI: 1.1-1.7]) or acenocoumarol (CC genotype 3.2 mg/d [95% CI: 2.9-3.5], CT genotype 2.3 mg/d [95% CI: 2.1-2.5], TT genotype 1.7 mg/d [95% CI: 1.3-2.1]) than CC genotype control patients. Compared with CC genotype individuals, carriers of at least one T allele had an increased risk of bleeding in the phenprocoumon users (crude odds ratio = 2.6, 95% CI: 1.2-5.7), but not in acenocoumarol users (crude odds ratio = 1.2, 95% CI: 0.6-2.3). CONCLUSION: These findings encourage taking further steps towards the evaluation of the use of VKORC1 genetic testing for bleeding prevention in individuals who receive VKA therapy.

Acenocoumarol↗

PubMed1997

Prediction of left ventricular mass changes after renal transplantation by polymorphism of the angiotensin-converting-enzyme gene.

Cardiac complications are the main cause of death in renal transplant patients and left ventricular hypertrophy (LVH) may play a determinant role. An association between the insertion-deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and LVH has been reported in adults. However, little is known about the genetic influence on left ventricular mass changes after renal transplantation, where unique environmental factors, such as cyclosporine A (CsA) and prednisone treatment concur. In fact, CsA treatment has recently been associated with the development of LVH. We prospectively determined the changes on cardiac structure and function, assessed by echocardiographic criteria, in 38 consecutive nondiabetic adults who received a cadaveric renal allograft. They were treated with cyclosporine and prednisone and maintained a good renal function during the follow-up. Echocardiographic studies (M-mode, 2-B and color flow Doppler) were performed without previous knowledge of the genetic typing, at the time of transplantation, and 6 and 12 months later. ACE alleles were typed using a PCR-based assay developed to ascertain the presence of an insertion (I)-deletion (D) polymorphism in intron 16 of the ACE gene. Patients with the so-called "unfavorable" DD genotype (N = 16) were compared with the ID or II genotypes (N = 22). The baseline left ventricular mass index was similar in patients with or without the unfavorable DD genotype (X +/- SE; 166.6 +/- 10.4 vs. 181.3 +/- 9 g/m2, respectively) and a similar proportion fulfilled the criteria of LVH (88% vs. 82%, respectively). The mean percent increase of the left ventricular mass index 12 months after renal transplantation was significantly higher in patients with the DD genotype compared to those with other genotypes (21.3 +/- 7.9 vs. -0.08 +/- 4.9%, respectively; P < 0.05). As a result, 94% of DD patients showed LVH at the end of the follow-up, while 68% of the ID or II patients had LVH (P < 0.05). In addition, the left ventricular ejection fraction significantly increased only in ID or II patients 12 months after transplantation with respect to baseline (ID/II patients, 70.4 +/- 1.5 vs. 63.7 +/- 1.8%; P < 0.05; DD patients, 68.3 +/- 2.1 vs. 63.3 +/- 2.9%). The deleterious effect of the DD genotype was independent of blood pressure, biochemical parameters, weight gain, and cumulative steroids dosages or cyclosporine levels. In conclusion, genetic factors determine the changes on cardiac structure and function after renal transplantation. The presence of the DD genotype of the ACE gene is a marker associated with an elevated risk of LVH in this population.

Adult↗

PubMed1999

A characterization of genetic variants in BRCA1 intron 8 identifies a mutation and a polymorphism.

The biochemical and genetic characterizations of two variants that occur in BRCA1 intron 8 are presented. The variant IVS8+2T-->C induces an aberrant transcript that deletes exon 8. This exon-skipping deletion disrupts the open reading frame by juxtaposing exon 7 and exon 9 in the aberrant splice product. Theoretically, 50 abnormal residues from reading frame 2 are translated following exon 7 before a stop codon is encountered. The chromosomal contribution to the relevant RNA species was tracked using a silent polymorphism at codon 694 (serine AGC or AGT). Nucleotide sequencing of this polymorphic codon demonstrated that the aberrant transcript was derived solely from the chromosome encoding AGT. The normally spliced productive transcript also displayed loss of heterozygosity and was derived solely from the chromosome encoding AGC at codon 694. Also, a haplotype analysis using a breast cancer patient database showed that the chromosome bearing serine 694-AGT carried IVS8+2T-->C. A second more common variant, IVS8-58delT, was characterized as a polymorphism. Analysis of RNA from patient samples used the same silent polymorphism at codon 694 and showed that the normal message was derived from both chromosomes.

BRCA1 Protein↗

PubMed2007

TAMGeS: a Three-array Method for Genotyping of SNPs by a dual-colour approach.

BACKGROUND: Many of the most effective high-throughput protocols for SNP genotyping employ microarrays. Genotypes are assessed by comparing the signal intensities that derive from the hybridization of different allele-specific probes labelled either by using four fluorescent dyes, one for each base, or by using only two dyes and investigating the polymorphic alleles two by two on separate arrays. The employment of only two dyes makes it possible to use a dual-laser scanner, which has the advantage of being present in every microarray laboratory. However, this protocol may present some drawbacks. To infer all the six possible genotypes it is necessary to compare signals from two arrays, but this comparison not always is successful. A number of systematic errors in the experimental protocol, in fact, may differently affect signal intensities on separate arrays. Here we present TAMGeS (Three-Array Method for Genotyping of SNPs), an exhaustive method for SNP genotyping through SBE (Single Base Extension) and dual-colour microarrays, which makes the comparison of signals on distinct arrays reliable by using a third array and a data handling method for signal normalization based on bilinear regression theory. RESULTS: We tested the effectiveness of the proposed method by evaluating the results obtained from the direct comparison of the two arrays or by applying TAMGeS, both on experimental and synthetic data. With synthetic data, TAMGeS reduced the frequency of errors by an order of magnitude, when the incidence of systematic errors was not negligible. With the experimental data, produced by genotyping 25 SNPs in 437 subjects, TAMGeS reduced the percentage of missing genotypes from 54% (Two-Array Method) to 14.5%. Allelic and genotypic call rates were 99.3% and 99.5%, respectively. The normalization procedure takes into account also systematic errors, which can be generated by a time-delayed assay, thus making the protocol more flexible. CONCLUSION: TAMGeS represents an innovative method, which proved to be very effective in producing reliable SNP genotyping data by dual-colour microarrays. The requirement of a third array is well balanced by the strong enhancement in data quality and by the greater flexibility of the experimental protocol.

Base Sequence↗

PubMed2002

Influence of the endothelial nitric oxide synthase polymorphism on the progression of autosomal dominant polycystic kidney disease and IgA nephropathy.

BACKGROUND: The reason of variability of clinical course and progression to end-stage renal failure (ESRF) of two widespread chronic nephropathies-autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IGAN) is not clear. The endothelial dysfunction is considered in the number of factors possibly influencing the prognosis of these nephropathies. Our study tried to verify the hypothesis that endothelial nitric oxide synthase (ecNOS) gene polymorphisms in intron 4 could have some relevance to the progression of ADPKD and/or IgA nephropathy. METHODS: We examined 128 Czech patients with ADPKD (62 males, 66 females) and 93 patients with IGAN (51 males, 42 females). As a control group we used 100 genetically unrelated healthy subjects (50 men, 50 women, mean age 51.2 +/- 8.2). The genomic DNA was amplified by polymerase chain reaction (PCR) and the products were separated on 1.5% agarose gel and visualized by ultraviolet transillumination. We compared homozygous subjects for ecNOSb allele with homozygous and heterozygous subjects for ecNOSa allele. RESULTS: The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 19% (19/100) and 81% (81/100) in the control group. The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes in ADPKD patients were: 26.6% (8/30) and 73.4% (22/30) in ADPKD patients with normal renal function, 30% (9/30) and 70% (21/30) in ADPKD with ESRF, 35.2% (18/51) and 64.8% (33/51) in young ADPKD patients, 60% (12/20) and 40% (8/20) in ADPKD patients with ESRF later than in 62 years. In IGAN the frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 24% (12/50) and 76% (38/50) in IgA with normal renal function and 20.9 % (9/43) and 79.1% (38/43) in IgA with ESRF. CONCLUSION: Both in ADPKD and IGAN groups there was no significant difference in the frequencies of ecNOS genotypes between patients with normal renal function and age matched patients with ESRF and between patients with normal renal function and control group. The frequency of ecNOS a allele was significantly higher in a number limited group ADPKD patients with ESRF later than in 62 years (Chi-square test p < 0.05). This higher frequency of a allele among ADPKD patients with later onset of ESRF could suggest the trend of positive influence of a allele in ADPKD patients.

Disease Progression↗

PubMed1999

The renin--angiotensin system gene polymorphisms and clinicopathological correlations in IgA nephropathy.

Genetic variability in the renin-angiotensin system (RAS) may modify renal responses to injury and disease progression. We examined whether RAS alleles affect severity of IgA nephropathy. These genetic variants include angiotensin I converting enzyme deletion polymorphism in intron 16 (ACE I/D), a point mutation in the angiotensinogen (AGT) gene resulting in a methionine to threonine substitution at residue 235 (M235T) and an angiotensin receptor type I (ATR) A to C transition at bp 1166 (A 1166 C). A total of 53 patients with biopsy-proven IgA nephropathy and 80 normal control subjects were recruited for study. These patients were classified into two groups according to serum creatinine at renal biopsy. Group 1 patients (n = 40) had normal renal function, serum creatinine < or = 1.5 mg/dl and group 2 patients (n = 13) had renal insufficiency with serum creatinine > 1.5 mg/dl. The blood pressure and urinary protein of group 2 patients were higher than group 1 (p < 0.01). The mean scores of histological parameters including mesangial proliferation, glomerular sclerosis (global and segmental), the interstitial fibrosis and crescent formation in group 2 patients were significantly higher than in group 1 patients (p < 0.05). The most frequent genotype in IgA patients was ID (47%) genotype, followed by II (45%) and DD (8%) genotype of ACE gene. The mean serum ACE activity in the DD group was significantly higher than in the II group (p < 0.05) but was not significantly different from that of the ID group. No statistically significant differences were found with respect to allele frequencies between IgA group 1, group 2, or between controls and all IgA patients. Furthermore, no significant difference in AGT alleles, ATR alleles frequencies was detected between groups of IgA patients, although a trend for a higher frequency of DD genotype and AGT-TT genotype were noted in IgA group 2. The combined analysis of the ACE-DD and AGT-TT genotypes did not show any genetic influence on the risk of the disease susceptibility. To resolve the true role of ACE genotype and any dependent effect on progression, larger collaborative studies are required.

Adolescent↗

PubMed1993

Four novel gene mutations in five Japanese male patients with neonatal or late onset OTC deficiency: application of PCR-single-strand conformation polymorphisms for all exons and adjacent introns [corrected].

Ornithine transcarbamylase deficiency (OTC), the most common inborn error of the urea cycle, shows an X-linked inheritance with frequent new mutations. Southern blots reveal only a small percent of the mutation, but amplification of cDNA or genomic DNA using the polymerase chain reaction (PCR) followed by DNA sequencing, has contributed greatly to overcoming this difficulty. Problems remaining are the limited availability of fresh liver samples for preparation of intact mRNA in the former case, and there are primer sequences for PCR for only some exons in the latter case. Here, we report the structures of intron sequences which are long enough to analyze all exons and adjacent introns of the OTC gene using PCR and PCR single-strand conformation polymorphisms (PCR-SSCP). We carried out a DNA analysis of findings in five Japanese male patients with neonatal or late onset form. Five patients had mutations in the protein coding region. C to G (S192R), A to T (D196V), A to G (T264A), T to C (M268T), and C to T (R277W) substitutions. The first four of these were novel missense mutations and the presence of the mutation was confirmed in the corresponding families.

Asian People↗

PubMed1999

Structural alterations of transforming growth factor-beta receptor genes in human cervical carcinoma.

The development and progression of invasive uterine cervical carcinomas appear to be associated with the progressive loss of sensitivity to transforming growth factor-beta (TGFbeta)-mediated cell cycle arrest. In order to identify possible molecular mechanisms responsible for TGFbeta resistance, we screened the 7 exons of the type II (TbetaR-II) TGFbeta receptor and the 9 exons of the type I (TbetaR-I) TGFbeta receptor genes for mutations in 16 paraffin-embedded primary invasive cervical carcinoma specimens. In one of these carcinomas, we found a novel G-->T transversion in exon 3 of TbetaR-II that introduces a premature stop codon (E142Stop) and presumably results in the synthesis of a truncated soluble exoreceptor. In one tumor, a silent A-->C transversion mutation that may affect mRNA splicing was present in exon 6 of TbetaR-I. In addition, 7 of 16 cases were heterozygous for a G-->A polymorphism in intron 7 of TbetaR-I. Finally, we identified a 9 base pair in-frame germline deletion in exon 1 of TbetaR-I resulting in loss of 3 of 9 sequential alanine residues at the N-terminus in 6 of 16 cases. Analysis of specimens from case-control studies indicated that carriers of this del(GGC)3 TbetaR-I variant allele may be at a increased risk for the development of cervical carcinoma (p=0.22). Furthermore, the response of cells expressing the variant receptor to TGFbeta was diminished. Our results support the notion that diverse alterations in the TGFbeta signaling pathway may play a role in the development of cervical cancer.

Adult↗

PubMed1987

Structure and evolution of human apolipoprotein genes: identification of regulatory elements of the human apolipoprotein E gene.

The structures of the major human apolipoprotein genes have been determined. The genes for apoE, apoC-I, apoC-II, apoC-III, apoA-I, apoA-II and apoA-IV have similar structures, consisting of four exons and three introns, which suggests that they evolved from a common ancestral gene. The third and fourth exons of the ancestral gene appear to have evolved from the duplication of a 66-nucleotide repeat unit that encodes a 22-residue alpha-helical peptide element of amphipathic character. The apoA-I, apoC-III and apoA-IV genes are linked closely within a 20-kilobase (kb) span of chromosome 11. The apoE and apoC-I genes, together with an apoC-I' pseudogene, are linked closely within a 25-kb span of chromosome 19. To characterize potential functional relationships among the apolipoprotein genes, initial studies have been done to identify the molecular elements involved in the regulation of the human apoE gene. Fragments of the 5'-flanking portion of this gene were inserted into appropriate plasmid vectors, which contained the bacterial chloramphenicol acetyl transferase gene, and were examined for promoter activity and potential enhancer activity after transfection into cultured mammalian cells. Deletion mapping of the promoter region has identified multiple functional elements, including an enhancer, two G-C boxes (Sp 1 transcription factor binding sites) and an upstream control element. In addition, there is an enhancer located in the first intron. Interactions among these various control elements are likely to determine the ways in which the expression of the apoE gene is regulated.

Apolipoproteins E↗

PubMed2001

Tryptophan hydroxylase gene variant and smoking behavior.

Approximately 50% of the variance in smoking behavior is attributable to genetic factors. Genes in the serotonin system are plausible candidates because of serotonin's role in mood regulation. The present study examined the association of smoking behavior with a polymorphism in the TPH gene, which codes for a rate limiting enzyme in the biosynthesis of serotonin. A polymorphism in intron 7 has been linked with a variety of traits involving poor impulse control. Participants in this study were 249 Caucasian smokers and 202 nonsmokers recruited through newspaper advertisements. Smokers completed smoking history and nicotine dependence assessments. The overall frequencies of the A- and C-allele were 42% and 58%, respectively. There was no association of TPH alleles with smoking status. However, case series analysis indicated that individuals with the A/A genotype started smoking at age 15.6 years, compared with 17.3 years among smokers with other genotypes. This association was significant in a multivariate regression model controlling for age, education, body mass index (BMI), alcohol use, and medication use. This finding is consistent with previous studies relating the A-allele to impulsive behavior and suggests that it may predispose to early smoking initiation. Future family-based studies are needed to confirm this finding. Published 2001 Wiley-Liss, Inc.

Adult↗

PubMed1993

Exon 44 nonsense mutation in two-Duchenne muscular dystrophy brothers detected by heteroduplex analysis.

Utilizing a heteroduplex method, we screened the dystrophin exon 43-45 region for point mutations, including small deletions and insertions. The method depends upon the formation of a heteroduplex between wild-type and mutant DNA PCR products. DNA specimens from one hundred and four DMD patients without detected deletions or duplications were multiplexed amplified for exons 43, 44, and 45. The PCR products were mixed with the PCR products from nonaffected controls, electrophoresed, and examined for the presence of altered mobility heteroduplex bands. An exon 44 nonsense mutation in two DMD brothers and a common intron 44 polymorphism were identified using this approach. Although the exon 44-45 region is a hotspot for deletion breakpoints, it does not appear to be prone to point mutations. The technique is extremely useful for screening several exons simultaneously and it allowed us to screen a large number of patients.

Base Sequence↗

PubMed2004

Dietary calcium, vitamin D, VDR genotypes and colorectal cancer.

The vitamin D receptor (VDR) may importantly modulate risk of colorectal cancer either independently or in conjunction with calcium and vitamin D intake. We evaluate the association between calcium, vitamin D, dairy products, and VDR polymorphisms in 2 case-control studies of colon and rectal cancer (n = 2,306 cases and 2,749 controls). Dietary intake was evaluated using a detailed diet history questionnaire. Two VDR polymorphisms were evaluated: an intron 8 Bsm 1 polymorphism and a 3' untranslated region poly-A length polymorphism (designated S for short and L for long). The SS genotype reduced risk of colorectal cancer for men (odds ratio [OR] = 0.71; 95% confidence interval [CI] = 0.55-0.92). High levels of calcium intake reduced risk of rectal cancer in women (OR = 0.39; 95% CI = 0.24-0.64) but were not associated with rectal cancer in men (OR = 1.02; 95% CI = 0.66-1.56). Similar reduced rectal cancer risk among women was observed at high levels of vitamin D (OR = 0.52; 95% CI = 0.32-0.85) and low-fat dairy products (OR = 0.61; 95% CI = 0.39-0.94). High levels of sunshine exposure reduced risk of rectal cancer among those diagnosed when <60 years of age (OR = 0.62, 95% CI = 0.42-0.93). Examination of calcium in conjunction with VDR genotype showed that a significant 40% reduction in risk of rectal cancer was observed for the SS or BB VDR genotypes when calcium intake was low (p interaction = 0.01 for calcium interaction). For colon cancer, high levels of dietary intake of calcium, vitamin D, and low-fat dairy products reduced risk of cancer for the SS or BB VDR genotypes, although the p for interaction was not statistically significant. These data support previous observations that high levels of calcium and vitamin D reduce risk of rectal cancer and provide support for a weak protective effect for the SS and BB VDR genotypes. The risk associated with VDR genotype seems to depend upon the level of dietary calcium and vitamin D and tumor site.

Adult↗

PubMed2000

Differences in the genotypes and plasma concentrations of the INTERLEUKIN-1 receptor antagonist in black and white South African asthmatics and control subjects.

The allelic frequency of a variable tandem repeat (VNTR) polymorphism in intron 2 of the IL-1 Ra gene was studied in black and white patients with asthma as well as control individuals. The plasma IL-1 Ra concentration was also determined in asthmatics and compared to control individuals. The 410-bp allele of the IL-1 Ra was significantly increased in all black subjects (90%) as compared to all white subjects (74%, P<0.0001), while the 240-bp allele was significantly reduced in all black subjects (11%) as compared to all white subjects (27%, P<0.0001). There was no difference in the frequency of the VNTR of the IL-1 Ra between black asthmatics and black controls and between white asthmatics and white controls. The IL-1 Ra levels were significantly increased in black and white patients with severe or moderate asthma as compared to patients with mild asthma. Increased plasma concentrations of the IL-1 Ra was found to be associated with disease severity in all asthmatic patients.

Adolescent↗

PubMed1994

Mutational analysis of the amyloid precursor protein gene in Japanese familial Alzheimer's disease kindreds.

We sequenced the entire coding region of the amyloid precursor protein (APP) genes of 11 unrelated patients with Japanese familial Alzheimer's disease (FAD) in order to determine the exact frequency of known APP gene mutations and to search for novel mutations responsible for FAD. Three out of 11 (27.3%) FAD patients showed the known Val to Ile mis-sense mutation at codon 717, but no other mutations were detected in the entire coding region. Analysis of exons 16 and 17 in 30 Japanese with sporadic AD revealed no mutations. Moreover, there were no significant differences in the allele frequencies of the DNA polymorphism in intron 9 among the 11 FAD, 39 sporadic AD, and 110 control subjects.

Adult↗

PubMed1987

A new HindIII restriction fragment length polymorphism in the hemophilia A locus.

Using a fragment of the cDNA for human coagulation factor VIII as a hybridization probe, we have detected a new polymorphic HindIII site in intron 19 of the factor VIII gene. The frequency of the minor allele is 0.30. This polymorphism shows strong linkage disequilibrium with a previously described BclI polymorphism in intron 18.

Alleles↗

PubMed1998

Genomic structure of TBX2 indicates conservation with distantly related T-box genes.

TBX2 is a member of a recently discovered gene family of transcription factors, named T-box genes after the Brachyury or T gene. Mutations in two of these family members, TBX5 and TBX3, have recently been shown to be responsible for the congenital abnormalities associated with Holt Oram syndrome and ulnar-mammary syndrome respectively, while mutations in T-box genes in other species also result in developmental abnormalities in the tissues where the gene is normally expressed. Thus, it likely that other T-box genes are responsible for additional human developmental anomalies. Here we report the exon/intron boundaries of TBX2 and a polymorphism within intron 2 of TBX2 that should be useful for exploring the involvement of this gene in human genetic disease. We further note that the exon/intron boundaries of TBX2 are highly conserved within the T-box domain with those of both T and TBX5, as well as with a new human T-box gene and more distantly related genes from Caenorhabditis elegans and Drosophila. This observation should facilitate the analysis of the genomic structure of other members of this gene family. It is also of interest that several members of this gene family have an additional intron that is variably present within members of at least two different lineages of the T-box family. This observation has implications regarding the evolution of T-box genes.

Animals↗

PubMed2001

New insights into allelic diversity of a phosphoeno/pyruvate carboxylase in the conifer Picea abies (l.) Karst.

Two genomic full-length alleles of a phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) were isolated and analysed in the gymnosperm Norway spruce [Picea abies (L.) Karst.]. Mendelian segregation analysis confirmed that the two alleles belong to the same DNA gene locus. Southern analysis was performed using exon and intron probes, separately. A small gene family was discovered when exon probes were used. The isolated gene locus was termed PEPC-1 and found to exhibit the largest PEPC genomic sequence characterised so far in the plant kingdom. This is due to comparatively long intron sequences, and to an additional intron in the 3'-untranslated region. Sequence homology of the two full-length PEPC-1 alleles is 99.8%. From exon variation, one single exchange of an amino acid was deduced. The introns harboured polymorphic regions that were analysed for variability among three different spruce individuals. Within-PEPC-1 genotyping revealed that all three individuals could be unambiguously distinguished from each other. The results are discussed with respect not only to exon/intron site evolution among alleles but also to particular genomic features of a gymnosperm PEPC in comparison to PEPC in angiosperms.

Alleles↗