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Results for “Polymorphism, Restriction Fragment Length”

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PubMed1995

Ovarian carcinoma-associated TaqI restriction fragment length polymorphism in intron G of the progesterone receptor gene is due to an Alu sequence insertion.

Alu sequences, short, repetitive transposable DNA elements, are factors in a number of genetic diseases. We previously identified a germline TaqI RFLP, located in intron G of the human progesterone receptor gene, that showed an association with the incidence of sporadic ovarian carcinoma. Furthermore, the polymorphism was characterized as a small (approximately 300-bp) insertion that was inherited in a Mendelian fashion. Because of its insertional character, we named this polymorphism PROGINS. We report the identification of PROGINS as a 306-bp Alu element of the PV or HS-1 Alu subfamily.

Alleles↗

PubMed2005

Identification of brucella species and biotypes using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Brucellosis is a worldwide zoonosis causing reproductive failures in livestock and a severe multi-organ disease in humans. The genus Brucella is divided into seven species and various biotypes differing in pathogenicity and host specificity. Although Brucella spp. represent a highly homogenous group of bacteria, RFLPs of selected genes display sufficient polymorphism to distinguish Brucella species and biovars. PCR-RFLP analysis shows excellent typeability, reproducibility, stability, and epidemiological concordance. Consequently, PCR-RFLP assays of specific gene loci can serve as tools for diagnostic, epidemiological, taxonomic, and evolutionary studies. Various PCR-RFLPs used for the identification of Brucella species and biotypes are reviewed.

Bacterial Outer Membrane Proteins↗

PubMed1994

[Restrictive fragment length polymorphism analysis of gamma-crystallin in congenital cataract families].

Using gamma-crystallin gene probe P5G1, we investigated the RFLP in two large families of congenital cataracts and normal people, calculated the allelic gene frequency and defined the haplotypes by genetic linkage analysis. In accordance with foreign reports, TaqI/p5G1 detected 3 polymorphic sites, and the allelic gene frequency was close to that in foreign reports. However, foreign reports claimed that the haplotype P was linked to Coppock cataracts, but we did not find such linkage by haplotype analysis. The result suggests that not all the inherited cataracts are linked to gamma-crystallin gene, and the haplotype P should not be simply regarded as genetic marker in prenatal diagnosis.

Cataract↗

PubMedDate not supplied

[Use of molecular DNA probes in the diagnosis of mucoviscidosis-- analysis of restriction fragment length polymorphisms (RFLP) in 22 high-risk families].

The results of DNA analysis with the aid of specific molecular probes are discussed. DNA analysis involved 22 families of a high risk of cystic fibrosis. A significance of the obtained results in genetic counselling is also discussed. DNA analysis enabled detection or exclusion of cystic fibrosis gene carrier state in patient's relatives. DNA analysis proved fully informative in case of 17 families being a base to offer these families prenatal diagnosis of the disease in the I trimester of pregnancy, if such a family plans conception, and to accept this diagnostic technique.

Adolescent↗

PubMed1991

[Carrier detection of Glanzmann's thrombasthenia by Taq I restriction fragment length polymorphism of GPIIIa gene].

Glanzmann's thrombasthenia (GT) is an autosomal recessive bleeding disorder in which platelets fail to aggregate in second hemostasis due to qualitative and/or quantitative defect in their GPIIb/IIIa complex. In the present study, both phenotypic and genotypic assays were performed by Western blot and Southern blot techniques in 13 members of 3 GT families. 2 GT carriers of 3 probable carriers whose clinical features and GPIIb/IIIa protein were essentially normal were determined by Taq I/5' GPIIIa RFLP. There were no major deletion or insertion in GPIIIa gene in 4 patients with GT. Thus, the genetic defects in these patients is most likely due to a small change or point mutation in the nucleotide sequence of GPIIIa coding region.

Adolescent↗

PubMedDate not supplied

IgA2 allotypes determined by restriction fragment length polymorphism in IgA deficiency. Re-expression of the silent A2m(2) allotype in the children of IgA-deficient patients.

IgA2 allotyping was performed on DNA from 60 IgA-deficient Caucasian individuals. The frequency of A2m(2) was not statistically different from that of normal controls. Two informative families were selected for further studies. In both families, the A2m(2) allotype (derived from the IgA-deficient parent) was inherited by some of the children, as determined by Southern blotting experiments. In all cases the 'silent' IgA2m2 gene was re-expressed, as judged by conventional serological allotyping of serum proteins. These data strongly argue against structural gene deletions or mutations as a cause of IgA deficiency.

Alleles↗

PubMed1992

The NM23 gene maps to human chromosome band 17q22 and shows a restriction fragment length polymorphism with BglII.

The NM23-Hl gene is a putative tumor suppressor gene that may be important in the metastasic process. Recent genetic and immunological data indicate that the NM23-Hl gene encodes a protein with nucleoside diphosphate (NDP) kinase activity. The mapping of NM23-Hl by panels of rodent-human somatic cell hybrids and in situ hybridization showed that the gene is located in human chromosome band 17q22. A two-allele polymorphism with BglII was demonstrated.

Alleles↗

PubMed1995

Isoenzyme, restriction fragment length polymorphism, and random amplified polymorphic DNA characterization of Phaffia rhodozyma Miller et al.

The validity of the species concept was examined with strains of Phaffia rhodozyma by comparing the isoenzyme profiles, ribosomal DNAs, and random amplified polymorphic DNA (RAPD) patterns of the strains. The isoenzyme profiles appeared to be more stable than the RAPD patterns or the electrophoretic karyotypes determined previously (A. Nagy, N. Garamszegi, C. Vágvölgyi, and L. Ferenczy, FEMS Microbiol. Lett., in press). The ribosomal DNA patterns revealed only a limited degree of variability, while RAPD analysis proved to be the most useful method for differentiating the strains studied. Strain CBS 5905T (T = type strain) produced characteristic RAPD patterns, which were different from those produced by the other strains. However, despite the high degree of variability observed, the isoenzyme data and the slightly variable ribosomal DNA hybridization profiles confirmed that the strains which we examined belong to one species.

Base Sequence↗

PubMed1987

The use of multiple restriction fragment length polymorphisms in prenatal risk estimation. II. Conditional risk distributions.

Although analytical procedures for multiple marker risk estimation are now well established, we still lack a unified optimal procedure for deciding which family members to examine and which markers to use. Towards this goal, the application of conditional risk distributions is developed, along with a suggested statistic for judging the utility of a marker. The conditional risk distribution depends on what knowledge has already been obtained about the pedigree, and indicates the expected outcome of risk estimates after another marker is examined. Population genetic aspects including haplotype frequencies, linkage disequilibrium, family size and pedigree structure and the statistical confidence in the linkage map all influence the optimal strategy for multiple marker risk estimation.

Gene Frequency↗

PubMed1992

Effect of storage conditions on restriction fragment length polymorphism (RFLP) analysis of deoxyribonucleic acid (DNA) bound to positively charged nylon membranes.

The ability to generate an autoradiogram from deoxyribonucleic acid (DNA) immobilized on a positively charged nylon membrane could be compromised by the storage conditions of the membrane. HaeIII-digested human DNA was size fractionated and transferred to two types of positively charged nylon membranes. The membranes were stored at -20 degrees C, 4 degrees C, and ambient temperature and humidity for times ranging from 1 day to 13 weeks, then hybridized to variable number of tandem repeat (VNTR) probes to examine the effect of the storage conditions on the membrane-bound DNAs. It was shown that such membranes could be successfully hybridized and rehybridized if they were stored at -20 or 4 degrees C, but storage under ambient conditions reduced or eliminated the likelihood of successful hybridization.

Autoradiography↗

PubMed1991

A genetic linkage map of 41 restriction fragment length polymorphism markers for human chromosome 3.

A genetic linkage map for human chromosome 3 has been constructed using 41 polymorphic DNA markers genotyped in 40 CEPH reference families. The map spans a genetic distance of 261 cM in males and 413 cM in females; the ratio of these distances (approximately 1.6 in favor of female meioses) was fairly constant across the map. Frequency of recombination was relatively uniform throughout much of the chromosome, except that in both telomeric regions recombination was more frequent than the physical distances would predict. The genetic map was basically in agreement with physical localization of 24 loci that were mapped by fluorescent in situ hybridization. This map can be used for linkage studies for genetic diseases, and it will serve as a step toward a high-resolution map for human chromosome 3.

Chromosome Mapping↗

PubMed1990

Defective, deleted or converted CYP21B gene and negative association with a rare restriction fragment length polymorphism allele of the factor B gene in congenital adrenal hyperplasia.

Defects in the enzyme, steroid 21-hydroxylase, result in congenital adrenal hyperplasia (CAH), a common autosomal recessive disorder of cortisol biosynthesis. The gene encoding this protein (CYP21B) and a closely linked pseudogene (CYP21A) have been mapped in the HLA complex on chromosome 6p, adjacent to the complement genes C4B and C4A, about 80 kb from the factor B gene. Molecular analyses of patients with CAH have shown that the cause of the defect may be either a deletion, a point mutation or a conversion of the active gene. Linkage of the disease to HLA has previously been studied by several groups. We have analyzed DNAs from patients with classical and non-classical CAH and from their family members, by probing with CYP21, C4 and BF cDNAs. In 70% of the CAH haplotypes studied, the defective CYP21B gene was indistinguishable from its structurally intact corresponding gene in Southern blot analysis, and presumably bore point mutations. In the remaining chromosomes, evidence for gene conversions, deletions and various deleterious mutations of the CYP21B gene is given. Moreover, our linkage studies show that a polymorphic TaqI cleavage site in the factor B gene, recently described by us, may be a new and useful genetic marker, because we found this TaqI restriction site only in unaffected haplotypes carrying functional CYP21B genes and, therefore, in negative association with the defective CYP21B gene.

Adrenal Hyperplasia, Congenital↗

PubMed2000

Analysis of restriction fragment length polymorphisms of the insertion sequence IS1381 in group B Streptococci.

Group B streptococci (GBS) are typed by capsular polysaccharide type. IS1381, an insertion sequence previously described in Streptococcus pneumoniae, was cloned from GBS strain A909. The presence of multiple copies of IS1381 in A909 suggested that IS1381 analysis might be an effective subtyping tool. IS1381 was found by Southern blot analysis to be present in 18 (72%) of 25 of unrelated GBS isolates tested. IS1381 analysis allowed discrimination between strains that contain IS1381 with a discriminatory power >99%. Eight of 8 sets of epidemiologically related isolates containing IS1381 give identical or nearly identical patterns of IS1381 insertion. For 2 maternal/infant sets, a single additional insertion was seen in 1 strain, suggesting that an additional insertion occurred between maternal colonization and infection of the infant. Insertion patterns of IS1381 are an effective tool for subtyping GBS.

DNA Transposable Elements↗

PubMed1992

High levels of linkage disequilibria between serologically defined class I bovine lymphocyte antigens (BoLA-A) and class II DQB restriction fragment length polymorphism (RFLP) in Norwegian cows.

Serum defined BoLA-A antigens, together with BoLA-DQB RFLP patterns, were determined in 87 almost unrelated Norwegian cattle. Statistical analysis revealed strong linkage disequilibria between these loci at the population level. A total of 13 haplotypes were found to be present at frequencies significantly greater than those predicted on the basis of their component gene frequencies. Among these, the subgroups 1A and 1B of the DQ1 haplotype were found to be closely associated with the class I antigens A11 and w16, respectively. The association between A11 and DQ1A is of particular interest, as two independent studies, one employing class I serology, and the other RFLP analysis of the class II locus DQ, have previously indicated that A11 and DQ1A confer relative susceptibility to mastitis.

Alleles↗

PubMed1997

Study of the alcohol dehydrogenase-1 (Adh1) gene in tetraploid corn: expression in the pollen grains and restriction fragment length polymorphism.

The results of two separate experiment are presented in this paper. In the first experiment pollen assays were carried out in Wf9 tetraploid maize plants in order to decide whether the lack of the ADH enzyme activity in the pollen grains was caused by a 'O' allele or an active transposon. On the basis of the results we suppose that the reduced ADH enzyme activity in the pollen grains is the result of a transposon affecting only the gametophyte. In the second experiment a maize Adh1-S genomic clone was constructed by polymerase chain reaction (PCR) and used as a probe to detect polymoprhism around the Adh1 gene in W117 S18 tetraploid maize sublines. The PCR20-EcoRI clone-enzyme combination resulted in a monomorphic RFLP pattern. The PCR20-Bgl II probe-enzyme combination yielded a multiple-banded pattern.

Alcohol Dehydrogenase↗

PubMed1999

Simultaneous infection with two strains of Mycobacterium tuberculosis identified by restriction fragment length polymorphism analysis.

Simultaneous infection with two different strains of Mycobacterium tuberculosis has been demonstrated using phage typing. We report here the first case of mixed infection identified using IS6110-based genotyping of M. tuberculosis. The patient was diagnosed with pulmonary tuberculosis in February, 1991. The initial isolate of M. tuberculosis had two different genotype patterns (dark 7-band and light 14-band patterns). However, in a repeat isolate obtained several months later, only the 14-band pattern was visible. Exogenous reinfection and laboratory cross-contamination were unlikely because both genotype patterns were unique in the San Francisco database which includes over 1300 isolates of M. tuberculosis. This case demonstrates the importance of identifying mixed infections in the study of the molecular epidemiology of tuberculosis. Mixed infections could be confused with exogenous reinfection or laboratory cross-contamination, and important epidemiologic connections could be missed.

Antitubercular Agents↗

PubMed2001

Identification of Biomphalaria havanensis and Biomphalaria obstructa populations from Cuba using polymerase chain reaction and restriction fragment length polymorphism of the ribosomal RNA intergenic spacer.

In Cuba, several Biomphalaria species have been reported such as B. orbignyi, B. schrammi, B. helophila, B. havanensis and B. peregrina; only the latter three are considered as potential hosts of Schistosoma mansoni. The specific identification of Biomphalaria species is based on anatomical and morphological characters of genital organs and shells. The correct identification of these snails is complicated by the high variation in these characters, similarity among species and in some cases by the small size of the snails. In this paper, we reported the classical morphological identification, the use of PCR and RFLP analysis of the internal transcribed spacer region of the ribosomal RNA genes for molecular identification of seven snail populations from different localities in Cuba. Using morphological and molecular analysis, we showed that among the studied Cuban Biomphalaria populations only B. havanensis and B. obstructa species were found.

Animals↗

PubMed1999

Relation of the bi-allelic NcoI restriction fragment length polymorphism within the tumour necrosis factor B gene to the development of mediastinitis.

During recent years the dual role of endogenous inflammatory mediators such as tumour necrosis factor (TNF) has become evident. While TNF has been recognised to possess a great detrimental potential, for example in the case of sepsis, it is on the other hand an integral component of an adequate immune response to bacterial invasion. These different properties of TNF and others seem to be dependent mainly on the quantitative extent of their formation. Some recent findings indicate that this extent may in part be determined genetically. The classification of patients according to polymorphic cytokine genes might, therefore, predict some of their reactions to septic challenges.

Alleles↗