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Results for “Polymorphism, Restriction Fragment Length”

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At least 19 recordsLinked to original sources
PubMed1989

Lack of association between scleroderma and types I and III procollagen gene restriction fragment length polymorphisms.

Restriction fragment length polymorphisms (RFLPs) in types I and III procollagen genes were studied in 62 scleroderma patients and 138 healthy controls. Allelic frequencies were determined for each RFLP, and comparisons were made between the 2 populations, stratifying them by race when appropriate. No statistically significant differences were observed for the frequencies of any of the RFLPs studied.

Alleles↗
PubMed1990

Association of scleroderma with a T cell antigen receptor gamma gene restriction fragment length polymorphism.

Restriction fragment length polymorphisms (RFLPs) in the T cell receptor (TCR) alpha, beta, and gamma genes were analyzed in 61 scleroderma patients and 150 controls. An association was found between scleroderma and an 11.3-kb Pvu II fragment in the TCR gamma gene; this gene was found in 41.0% of the patients, compared with 21.7% of the controls (P less than 0.01, odds ratio = 2.50). There were no associations between scleroderma and the tested RFLPs in the TCR alpha or beta genes, and no RFLPs were found in the constant region of the TCR delta gene.

Alleles↗
PubMed1988

Genetic analysis of the fungus, Bremia lactucae, using restriction fragment length polymorphisms.

Restriction fragment length polymorphisms (RFLPs) were developed as genetic markers for Bremia lactucae, the biotrophic Oomycete fungus which causes lettuce downy mildew. By using 55 genomic and cDNA probes, a total of 61 RFLP loci were identified among three heterothallic isolates of B. lactucae. Of these 61 RFLP loci, 53 were heterozygous in at least one of the three strains and thus were informative for linkage analysis in at least one of two F1 crosses that were performed. Analysis of the cosegregation of these 53 RFLPs, eight avirulence loci and the mating type locus allowed the construction of a preliminary genetic linkage map consisting of 13 small linkage groups. Based on the extent of linkage detected among probes, the genome of B. lactucae can be estimated to be approximately 2000 cM. Linkage was detected between a RFLP locus and an avirulence gene, providing a potential starting point for chromosome walking to clone an avirulence gene. The high frequency of DNA polymorphism in naturally occurring isolates and the proper Mendelian segregation of loci detected by low copy number probes indicates that it will be possible to construct a detailed genetic map of B. lactucae using RFLPs as markers. The method of analysis employed here should be applicable to many other outbreeding, heterozygous species for which defined inbred lines are not available.

Blotting, Southern↗
PubMed1991

An epidemiologically valuable typing method for Neisseria meningitidis by analysis of restriction fragment length polymorphisms.

A restriction fragment length polymorphism (RFLP) typing method was developed for Neisseria meningitidis. A cloned EcoRI fragment from a Neisseria meningitidis Group B serotype 15P1.16 sulphonamide-resistant strain was used to probe Southern blots of total chromosomal DNA restriction fragments (enzyme AvaI). A group of 75 apparently unrelated organisms gave rise to 26 different restriction fragment length patterns and two different groups of epidemiologically related strains had RFLP patterns that were distinct for each group. The technique was highly reproducible and discriminatory. The RFLP data were compared with the results of serotyping and subtyping and isoenzyme electrophoretotyping. The RFLP data were consistent with those from the alternative typing methods; clones defined by isoenzyme analysis were subdivided by this technique. The use of RFLP typing by cloned probes should be of considerable epidemiological value.

Blotting, Southern↗
PubMed1990

A method for typing strains of Legionella pneumophila serogroup 1 by analysis of restriction fragment length polymorphisms.

A restriction fragment length polymorphism (RFLP) typing method for Legionella pneumophila serogroup 1 was developed. The method depended upon the use of cloned EcoR1 fragments from L. pneumophila (Knoxville-1) probing Nci1 restriction fragments of chromosomal DNA. Examination of strains of L. pneumophila which were apparently unrelated showed that inter-strain RFLPs were common, and these formed the basis of the typing scheme. The technique was found to be highly reproducible and discriminatory. When the RFLP data were compared to that obtained by monoclonal antibody (MAb) subgrouping both methods of strain differentiation gave consistent results. The isolates examined by either method were also sub-divided by the alternative technique. The analysis of RFLPs by cloned probes should be of considerable epidemiological value.

Antibodies, Monoclonal↗
PubMed1992

Mother-to-infant vertical transmission and cross-colonization of Streptococcus pyogenes confirmed by DNA restriction fragment length polymorphism analysis.

Restriction fragment length polymorphism (RFLP) analysis of total DNA and of ribosomal DNA (rDNA) regions (ribotyping) were used to document Streptococcus pyogenes vertical mother-to-infant transmission and to investigate the spread of S. pyogenes in an obstetric unit. Two isolates from a newborn, two isolates from his mother (patient 1), and two isolates from two other mothers (patients 2 and 3) were studied. RFLP of total DNA, both after HindIII and PvuII digestions and ethidium bromide staining, gave indistinguishable patterns for the strains isolated from the neonate, his mother, and patient 2. Strains from patient 3 and six unrelated strains studied for comparison showed different patterns. In our system, ribotyping was less discriminative than total DNA RFLP analysis. DNA RFLP analysis therefore provides a valuable molecular tool for studying S. pyogenes epidemiology.

Adult↗
PubMed1987

Differential diagnosis of genetic disease by DNA restriction fragment length polymorphisms.

DNA restriction fragment length polymorphisms (RFLPs) are used for diagnosis of genetic disease in families known to be affected by specific disorders, but RFLPs can be also useful for the differential diagnosis of hereditary disease. An RFLP pattern represents the inheritance of chromosomal markers in a family, and such a pattern may be compatible with the inheritance of a certain disorder in that family. Probabilities to find such a pattern if the disorder were present and if it were absent can be combined with the prior probabilities of disease considered in the differential diagnosis on the basis of previous clinical and laboratory data. Bayes' theorem is used to calculate the posterior probabilities of the diseases in question. This approach is illustrated in a family suffering from either spinal muscular atrophy (an autosomal recessive disease) or Becker muscular dystrophy (an X-chromosomal disorder). Probabilities to exclude a certain disorder can be calculated in advance, as some RFLP patterns are not compatible with the presence of that disorder.

Bayes Theorem↗
PubMed1990

Nucleic acid probe characterizes Leptospira interrogans serovars by restriction fragment length polymorphisms.

Restriction endonuclease analysis (REA) of genomic DNA can discriminate between many Leptospira interrogans serovars. However, several serovars have similar restriction endonuclease digestion patterns which prohibits accurate identification. This investigation expands previous REA studies of L. interrogans to include serovars in serogroup Tarassovi. Most serovars in this serogroup had characteristic digestion patterns by which they could be identified. However, four of the serovars in this serogroup had similar digestion patterns, thus preventing serovar identification by REA alone. To discriminate between these serovars REA was supplemented with Southern blot analysis. The DNA from each serovar showed similar but unique patterns when hybridized with a probe synthesized from a repetitive sequence element cloned from L. interrogans serovar hardjo type hardjo-bovis. The applicability of this technique to characterize other serogroups was assessed. One hundred sixty six of 190 serovars screened by Southern blot analysis contained sequences which hybridized with the repetitive element probe under conditions of relaxed stringency. These results suggest that Southern blot analysis using this probe will be a valuable supplement for typing L. interrogans.

Animals↗
PubMed1988

Close correlation between restriction fragment length polymorphism of the L-MYC gene and metastasis of human lung cancer to the lymph nodes and other organs.

Restriction length fragment polymorphism of the L-MYC gene was examined in DNAs from lung cancer tissues and normal tissues of 51 Japanese patients with lung cancer. In individual patients, no difference was seen between the restriction length fragments of the two alleles of L-MYC [6-kilobase (kb) and 10-kb fragments in EcoRI digests] in lung cancer tissues and normal tissues. But a striking correlation was found between the restriction length fragment polymorphism pattern of L-MYC and the extent of metastasis, particularly to the lymph nodes at the time of surgery: Patients with only the L band (10 kb) had few lymph node metastatic lesions, whereas patients with either the S band (6 kb) or the S and L bands almost always had lymph node metastatic lesion. A similar correlation was found between the presence of the S band and metastases to other organs. This correlation was particularly marked in cases of adenocarcinoma. These results indicate a clear genetic influence on metastases and a consequent poor prognosis for certain patients of lung cancer; L-MYC restriction length fragment polymorphism is thus shown to be a useful marker for predicting the metastatic potential of human lung cancer.

Adult↗
PubMed1987

A unique AT-rich hypervariable minisatellite 3' to the ApoB gene defines a high information restriction fragment length polymorphism.

A DNA restriction fragment length polymorphism has been found immediately 3' to the human apoB gene. Digestion of many different human DNAs at sites flanking the region and Southern blotting analysis reveal that this region can vary in length by approximately 300 base pairs with five alleles readily distinguishable. The length polymorphism is due to a unique AT-rich minisatellite that consists primarily of a 30-base pair tandem repeat with two structurally related subunit sequences, x (ATAATTAAATATTTT) and y (ATAATTAAAATATTT). In general, the sequences repeat in an x-y order. The AT-rich region also contains variant x and y sequences that result from C or G for A substitution. Sequence analysis of one large allele revealed the expected increased number of xy repeats. In addition, similar analysis of three different smaller alleles with the same apparent size on Southern blotting analysis showed that all were of slightly different size due to minor differences in the number of xy repeats. The heterogeneity of this AT-rich minisatellite provides the basis for a highly informative restriction fragment length polymorphism of the apoB gene and should be very useful in association and linkage analysis studies of the contribution of this locus to atherosclerosis susceptibility.

Alleles↗
PubMed1992

The inheritance of type I and type III von Willebrand's disease in Israel: linkage analysis, carrier detection and prenatal diagnosis using three intragenic restriction fragment length polymorphisms.

Three intragenic restriction fragment length polymorphisms (RFLPs) were used to study linkage and analyse the mode of inheritance in type I and type III von Willebrand's disease (vWD). In two families linkage was established between Sac I RFLPs and the inheritance of type I vWD. RFLP analysis of amniocyte DNA from a potentially affected foetus enabled us to establish a prenatal diagnosis of vWD in a third family with type I vWD. Linkage was also established in four families between the Sac I and two Taq I RFLPs and the inheritance of type III vWD. All type III probands were homozygotes and inherited the same mutant vWF allele from both parents. Heterozygous carriers from one type III family were phenotypically normal and could be detected only by linkage analysis, whereas carriers from the remaining three type III families were asymptomatic but had decreased values of vWF antigen and activity. RFLP-based linkage analysis of vWD alleles provides a way to improve the diagnostic precision, detect carriers, and may be useful for prenatal diagnosis of type III vWD.

Female↗
PubMed1987

[Genetic monitoring of laboratory rat strains by restriction fragment length polymorphisms of mitochondrial DNA].

Restriction fragment length polymorphisms of rat mitochondrial DNA (mtDNA) were examined using various kinds of laboratory rat strains in Japan. The results show that mtDNA of laboratory rats, Rattus norvegicus, are highly polymorphic; at least 7 types, Aa, Ba, Bb, Cb, Dc, Eb, and Fa, were found with the use of 6 restriction enzymes, EcoR I, Hind II, Hha I, Hpa II, Taq I, and Hinf I. Types Aa, Ba, and Eb were distributed widely in several strains, whereas types Ba, Cb, Dc and Fa were limited to some specific strains. These results indicate that restriction fragment length polymorphisms of mtDNA can be applied to genetic monitoring of laboratory rat strains.

Animals↗
PubMed1987

Neutrality tests of highly polymorphic restriction-fragment-length polymorphisms.

The allele frequency data of Baird et al. were tested using Ewens-Watterson sampling theory for goodness of fit to the infinite-alleles model of neutral evolution. Although probes of both the HRAS-1 and D14S1 loci identify highly diverse restriction-fragment-length polymorphisms, the observed values of gene identity (F) and the common allele frequency (C) are not significantly different from the neutral expectation. Allele frequency distributions show a tendency toward a deficit in diversity for HRAS-1 and a slight excess diversity for D14S1. The direction of these departures is consistent with potential selective effects of the Harvey-ras oncogene and hitchhiking of the D14S1 locus to closely linked immunoglobulin genes. Direct chi 2-tests of goodness of fit of the observed and expected allele frequency distributions reveal significant departures in the caucasoid and Hispanic HRAS-1 distributions but not in any of the other tests.

Alleles↗
PubMed1991

[Oncogene amplification and inactivation of tumor suppressor genes in urological malignant tumors--the application of restriction fragment length polymorphism analysis].

We applied restriction fragment length polymorphism (RFLP) analysis to 24 cases of renal cell carcinomas (RCC), 18 cases of prostate adenocarcinomas (PC), and 11 cases of transitional cell carcinomas (TCC) in the renal pelvis to study the oncogene amplification and inactivation of tumor suppressor genes. All of the cases showed no amplification nor gross rearrangements of the Harvey ras, c-myc, c-fos, c-myb, EGFR and PDGFR. In contrast, RFLP analyses demonstrated allelic losses interpreted as inactivational events of TSGs among the tumor forms studied. RCC had allelic losses on the short arm of chromosome 3 (3p) (68%), the long arm of chromosome 18 (18q) (33%), Y chromosome (29%), and 17p (27%) at high frequencies. PC showed frequent allelic losses on 16q (67%), 8p (50%), 18q (43%), 10p (40%), and 10q (38%). TCC had allelic losses on 17p (73%), 11p (64%), and 9p (40%). It was likely that the cases with the more malignant grade tumor had the more allelic losses.

Gene Amplification↗
PubMed1989

HLA-DR beta, -DQ alpha, and -DQ beta restriction fragment length polymorphisms in multiple sclerosis.

Restriction fragment length polymorphism (RFLP) studies were performed on DNA from unrelated Caucasian patients with multiple sclerosis (MS) using cDNA probes to the HLA class II genes DR beta, DQ alpha, and DQ beta. In a study of 34 patients and 34 controls who were not matched for DR type, we found that the DQ beta allele-specific RFLP or allogenotype, termed DQ beta lb, which corresponds at the molecular level to the DQwl serotype, is preferentially associated with MS. A significant disease association with DR2 was demonstrated by serology but this was not confirmed using DR2/Dw2-specific RFLPs. We suggest that DQ beta lb is largely responsible for HLA-associated susceptibility to MS and that the apparent MS-DR2 serological association is due to the strong linkage disequilibrium between DR2 and DQ beta lb. Homozygosity of one of the two allelic bands of the DX alpha gene, usually termed the DX alpha lower (DX alpha L) band (which cross-hybridizes with the DQ alpha probe), correlated with reduced susceptibility to MS. Similarly a 5.3 kb band identified by the DQ alpha probe in Mspl digests showed a negative correlation with MS. In an analysis of 27 DR2+ controls and 26 DR2+ patients it was found that these individuals all had DR2/Dw2-specific RFLPs and all had identical DR2/Dw2-associated DQ beta (DQ beta lb) and DQ alpha (DQ alpha lb) allogenotypes. We detected no polymorphisms of DR beta, DQ alpha, or DQ beta genes among the DR2+ MS patients which distinguished them from normals.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗