Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Restriction Mapping”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources

Isolation and characterization of human actin genes cloned in phage lambda vectors.

Using Drosophila and chicken actin probes, we have selected 14 human actin lambda recombinants from a genomic library. We present a restriction maps indicating the positions of the sequences homologous to actin and to an Alu probe. Restriction mapping has revealed that nine out of ten of these clones are distinct, indicating that actin is a multigene family. Hybrid elution of HeLa cell mRNA from filters containing the recombinant DNA, followed by in vitro translation and immunoprecipitation, as well as one- or two-dimensional protein analysis, shows that these recombinants code for actin. Hybridization back to human DNA digested with restriction enzymes shows that the EcoRI fragments of at least one of the lambda recombinants (lambda HA-5) result in similar-sized human DNA fragments in the intact genome. In nuclei, a 4.5-kb mRNA precursor to the cytoplasmic 1.9-kb mRNA can be detected by hybridization with genomic or cDNA probes, indicating the presence of additional sequences and RNA processing.

Actins↗

The thioester and isotypic sites of complement component C4 in sheep and cattle.

The region inclusive of the thioester and the isotype-determining sites of the sheep C4 genes from a single animal was amplified by polymerase chain reaction (PCR). Two bands, at 880 base pairs (bp) and 1000 bp, were resolved by agarose gel electrophoresis. Four different clones were obtained for the 880 bp (type 1) product and two from the 1000 bp (type 2) product. Two of the type 1 clones (type 1H) and both type 2 clones (type 2H) code for the PCPVIH sequence at the isotypic site whereas the other two type 1 clones (type 1D) code for the PFPVMD sequence. By restriction mapping and Southern blot analysis, there appears to be four C4 gene loci for the sheep: two type 1H, one type 1D, and one type 2H. The type 1H and type 2H genes are likely to code for proteins with C4B-like properties whereas the type 1D genes for proteins with C4A-like properties. The same region of the sheep C4 genes of nine other breeds of sheep are also amplified by PCR and analyzed by restriction mapping and Southern hybridization. Each of the sheep has type 1H, type 2H, and type 1D genes and appears to have four C4 gene loci except for the Orkney, which may have five. A single band of 880 bp was obtained from the PCR product from the genomic DNA of a single cow. Five different clones were identified, two of which code for the PFPVMD sequence and three for the PCPVIH sequence at the isotypic site, which is consistent with previous finding that C4 proteins with A- and B-like activities could be purified from the plasma of the same animal. Comparison of the nucleotide sequences of the isotype-determining region of the sheep and cattle C4 genes with those of the primates and mouse suggests that the C4A-like genes evolved independently in the primates and the ungulates.

Amino Acid Sequence↗

Transcripts encoding three types of guanylyl-cyclase-coupled trans-membrane receptors in inner ear tissues of guinea pigs.

The distribution of membrane-bound guanylyl cyclase (GC) transcription in inner ear tissues of the guinea pig was addressed by a reverse transcription-PCR approach using consensus primers flanking a region of about 630 bp in the intracellular domains in the target sequences. Restriction mapping of such amplificates obtained from cochlear and vestibular specimens permitted us to demonstrate GC-A, GC-B, and GC-C expression by differentiating overall PCR signals. This assay indicated that GC-A was expressed in the cochlea and vestibular organ. PCR products resulting from transcripts of the GC-B gene were obtained at considerably lower abundance than amplificates typical of the GC-A gene. The consensus primer approach with subsequent restriction mapping provided the opportunity to examine at the same time expression of GC-C in the inner ear and revealed the occurrence of GC-C transcripts in both inner ear compartments under investigation. The distribution pattern found by analysing the intracellular domains of membrane-bound guanylyl cyclases was confirmed by demonstrating transcription of the corresponding extracellular receptor domains. In addition, single-strand conformation polymorphism analysis of cDNA amplificates comprising the catalytic domain of guanylyl cyclases also indicated the presence of GC-C expression in the inner ear tissues examined. The GC-C transcripts detected in inner ear tissues appeared to correlate with functional receptor expression, since the production of cyclic GMP catalyzed by cochlear and vestibular specimens was stimulated by 1 microM of heat-stable enterotoxin to 18 and 80% above basal levels, respectively. Thus, GC-C may be involved in the fluid regulation by typical ligands (e.g., the peptide hormone guanylin or the toxins causing travellers' diarrhea), not only in the intestine but also in the organs responsible for hearing and gravitational orientation.

Animals↗

Entamoeba histolytica ribosomal RNA genes are carried on palindromic circular DNA molecules.

Highly abundant DNA fragments obtained after restriction enzyme digests of nuclear DNA of Entamoeba histolytica strain HM-1:IMSS have been cloned and characterized. Northern blot hybridization to E. histolytica rRNA and sequence analysis identified the abundant DNAs as ribosomal DNA containing species. Several overlapping clones containing these abundant DNAs were isolated from 4 different genomic libraries of E. histolytica. Alignment of the restriction maps was consistent with a circular molecule, about 24.6 kilobase pairs (kb) in size. Nuclease BA131 digestion provided additional evidence for the circular nature of this DNA. The ribosomal DNA molecule contains two large inverted repeat-regions, each at least 5.2 kb in length. Sequence analysis of clone R715 revealed homology to the large rRNA units of various eukaryotic organisms. This clone was located in both inverted repeats, suggesting two rRNA cistrons per molecule. The inverted repeats are flanked by stretches of DNA which contain tandemly reiterated sequences. Southern blot analysis of E. histolytica nuclear DNA revealed the presence of two populations of molecules. These molecules have identical arrangements of restriction sites, but differ in size (0.7 kb) in a fragment containing tandemly reiterated sequences. Analysis of E. histolytica nuclear DNA by electron microscopy also revealed circular molecules. These molecules are about 26.6 kb +/- 0.5 kb in size and contain structural features predicted by the restriction map of the extrachromosomal ribosomal DNA of E. histolytica.

Animals↗

XbaI, PstI, and BglII restriction enzyme maps of the two orientations of the varicella-zoster virus genome.

Cleavage of varicella-zoster virus DNA with the restriction endonucleases PstI, XbaI, and BglII resulted in 18, 22, and 20 fragments, respectively. Based on the molecular weights and molarities of these fragments, a molecular weight of 84 x 10(6) could be calculated for the varicella-zoster virus genome. In both the XbaI and the BglII patterns, four 0.5 M fragments were identified. The arrangement of the fragments was determined by molecular hybridization techniques, and the terminal fragments were identified by lambda exonuclease digestion. The 0.5 M fragments, of which two were located at the same terminus of the genome, contained repeated sequences: one terminally and one inverted internally. These results were in agreement with the existence of two equimolar subpopulations of the varicella-zoster virus genome, differing in the relative orientation of a short region of unique sequences. This region was bounded by the repeated sequences. From the molecular weights of the submolar fragments, a maximal molecular weight of 5 x 10(6) for the repeated region and a minimal molecular weight of 3.5 x 10(6) for the short unique sequence could be calculated.

Bacterial Proteins↗

Applications of consensus polymerase chain reaction with subsequent electrophoretic distinction of amplificates.

Conserved sequences within gene families permit the design of consensus primers that match several members of a given class of homologous genes. Polymerase chain reaction (PCR) products obtained with such consensus primers were characterized by restriction mapping or single-strand conformation polymorphism (SSCP) analysis, using precast polyacrylamide minigels and automated silver staining. Examples for the electrophoretic distinction of consensus amplificates are presented in the fields of guanylyl cyclase expression studies and in the determination of B-cell clonality in human blood samples. Guanylyl cyclase expression in inner ear tissues of guinea pigs was investigated by reverse transcription PCR using consensus primers with specificity for the subclass of particulate guanylyl cyclases. The resulting PCR products were assigned to three representatives of this group by restriction mapping. The consensus PCR approach enabled the detection of an unexpected receptor type, namely guanylyl cyclase C, in the inner ear. The distinction by SSCP analysis of denatured consensus amplificates was appropriate for the identification of clone-specifically rearranged immunoglobulin heavy chain genes of B-lymphocytes. Genomic DNA isolated from blood samples of leukemia patients served as the template for the consensus amplification of clone-specific VDJ rearrangements. Rapid distinction and re-identification of consensus PCR products was achieved by SSCP analysis for regular antigen receptor rearrangements and for t(14; 18) translocations. The potential of these procedures for detecting leukemia or lymphoma clones when monitoring minimal residual disease was assessed.

Animals↗

Analysis of respiratory syncytial virus strain variation in successive epidemics in one city.

The variability of respiratory syncytial virus isolates from five successive epidemics in an urban population was determined. A total of 187 isolates of respiratory syncytial virus from the southern part of Birmingham, United Kingdom, were classified into subgroups A and B and were then further assigned to genetic lineages. Allocation of isolates into lineages was achieved by reverse transcription of infected cell RNA and then PCR amplification of selected regions of the genome; PCR products were examined by restriction mapping or nucleotide sequencing of parts of the nucleoprotein gene, the small hydrophobic protein gene, and the attachment protein gene. Previous work has shown that estimations of genetic diversity by analysis of genes coding for proteins likely (attachment protein) and unlikely (nucleoprotein and small hydrophobic protein) to be under immune pressure gave concordant results. Six genetic lineages of subgroup A isolates have been defined by this procedure; these isolates differ by up to 20% in the amino acid sequences of their attachment proteins; likewise, subgroup B isolates can be divided into two categories by restriction mapping of parts of their nucleoprotein and attachment protein genes. The same genetic lineages appeared to be present worldwide during the same period. The analysis of isolates from successive epidemics showed that different lineages predominated in each epidemic and that not all lineages were present in every epidemic. Some lineages appeared to increase in numbers over several years and then decline, possibly indicating a buildup of resistance in the community to a particular genotype.

Capsid↗

Juxtaposition of the genes encoding Mycoplasma pneumoniae cytadherence-accessory proteins HMW1 and HMW3.

The loss and reacquisition of high-Mr (HMW) proteins, HMW1, 2, 3, 4 and 5, by Mycoplasma pneumoniae correlates with cytadherence phase variation. We are cloning and characterizing the genes encoding HMW1-5 to understand the mechanism regulating their coordinate expression. HMW1 was purified by polyacrylamide-gel electrophoresis. Amino acid (aa) sequence data were obtained from enzymatically generated peptide fragments from HMW1. A degenerate 17-mer probe synthesized based upon the aa sequence of one peptide clearly identified a single 4.75-kb BamHI fragment of M. pneumoniae DNA under stringent hybridization conditions. This fragment was cloned into pUC19 to generate pKV16. Restriction mapping of the 4.75-kb BamHI fragment in pKV16 revealed a possible overlap with the 9.4-kb EcoRI fragment containing the gene encoding protein HMW3. Southern blotting and reciprocal hybridization studies confirmed this overlap, establishing the juxtaposition of the genes encoding HMW1 and HMW3. Finally, physical mapping analysis by probing restriction fragments of M. pneumoniae DNA resolved by pulsed-field gel electrophoresis with the cloned genes encoding HMW1 and HMW3 revealed definitively that the hmw locus maps to a 106.8-kb ApaI fragment, rather than a 117.5-kb ApaI fragment, as had been reported previously for hmw3 [Krause and Mawn, J. Bacteriol. 172 (1990) 4790-4797].

Amino Acid Sequence↗

Studies on renin-2 gene in transgenic rats.

OBJECTIVE: To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. METHODS: A renin-2 gene restriction map was constructed by endonuclease digestion and Southern blotting hybridization. Transgenic rats were produced via microinjection method. RESULTS: The 24 kb fragments containing mouse full-length ren-2 and its flanking sequence were cleaved by single enzymes (EcoR I, Kpn I and BamH I) and combined enzymes (EcoR I/Kpn I, Kpn I/BamH I and BamH I/EcoR I), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full-length renin-1 cDNA were used in southern blotting hybridization. According to the electrophoresis and hybridization patterns, a ren-2 restriction map was constructed. 1603 fertilized rat ova after injection with purified 24 kb renin-2 gene were implanted into the oviducts of 81 pseudopregnant recipients in about 20 ova per female rat. 306 progenies were obtained from 50 foster mothers (average of pregnancies was 56.6%). 248 survived pups were identified by PCR analysis and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin-2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were harvested as the same as those reported in the literatures. A systemic observation and the problems occurred during production of transgenic rats were also described besides the technique procedure used in this study. CONCLUSIONS: Mapping of full-length murine ren-2 can be used in investigation of the structure and function of the gene. The results denoted that the ren-2 transgenic rats were successfully established in this study and the technique used in the production of transgenic rats was proved to be valid in leading to wide-spread application of transgenic technique to many other related researches.

Animals↗

Molecular characterisation of UK isolates of barley yellow mosaic bymovirus.

Several isolates of barley yellow mosaic virus (BaYMV) from different sites in the UK, including some that were virulent on European resistant winter barley cultivars (resistance-breaking strain: BaYMV-2) and some that were not, were examined by RT-PCR, restriction mapping and sequencing of selected parts of the virus genome. Nucleotide and predicted amino acid sequences were determined for the 5'-terminal region, part of the NIa coding region and the coat protein coding region on RNA 1 and an area at the N-terminus of the 70-kDa protein coding region on RNA 2. The sequences differed from those previously reported for a BaYMV isolate from Japan and for two German isolates, one of which was of the BaYMV-2 strain. There were no strain-specific amino acid differences and the few, non-consecutive, nucleotide differences detected were probably not significant and were insufficient to develop a rapid diagnostic test to distinguish BaYMV-2 from other isolates. Restriction mapping of RNA 2 cDNA again showed no consistent strain-related differences. The differences previously reported between the two German isolates are probably not strain-related.

Base Sequence↗

Pulsed field gel electrophoresis identifies a high degree of variability in the number of tandem 21-hydroxylase and complement C4 gene repeats in 21-hydroxylase deficiency haplotypes.

The human steroid 21-hydroxylase gene, CYP21B, and its closely homologous pseudogene, CYP21A, are each normally located centromeric to a complement C4 gene C4B and C4A respectively, in an organization suggesting tandem duplication of a CYP21 + C4 unit. Such an organization has been considered to facilitate gene deletion and addition events by unequal crossover between the tandem repeats. However, the large size (approximately 30 kb) of the individual CYP21 + C4 repeat units together with the difficulty in identifying reliable CYP21A- and CYP21B-specific markers has prevented direct monitoring of gene organization on individual haplotypes by conventional Southern analyses. In the present investigation we have sought to clarify the CYP21 and C4 gene organization in members of 32 British 21-hydroxylase deficiency families by employing additional experimental approaches, notably a long-range restriction mapping approach, which permits assessment through a VNTR type of analysis, of the number of CYP21 and C4 units on individual haplotypes. Our results show that there is a very high frequency (33%) of 21-hydroxylase deficiency haplotypes where functional CYP21B gene sequence has been removed as a consequence of CYP21 + C4 gene deletion while several haplotypes show evidence of gene addition. In each case that we have investigated the gene deletion and gene addition haplotypes differ in length from conventional haplotypes by integral multiples of approximately 30 kb, which strongly supports the involvement of unequal crossover mechanisms. Additionally, the comparatively frequent occurrence of CYP21 fusion genes which contain both CYP21A- and CYP21B-associated markers is suggested by the combined data from Southern analyses, long-range restriction mapping and characterization of selected regions of CYP21 genes which have been amplified in vitro.

Adrenal Hyperplasia, Congenital↗

Molecular analysis of the arylamine N-acetyltransferase polymorphism in a Spanish population.

The arylamine N-acetyltransferase (NAT-2) polymorphism causes impaired drug metabolism in about half of the white population. By the combined use of polymerase chain reaction (PCR) and restriction mapping with the endonucleases Fok I and Dde I, we have studied the genetic basis underlying NAT-2 polymorphism in genomic deoxyribonucleic acid from 245 healthy Spaniards. The study of three mutations at the NAT-2 gene locus by PCR analysis (namely, 481T, 590A, and 857A) revealed that all these mutations were present in Spaniards at similar frequencies as described in other white populations, strongly contrasting with genetic differences in the CYP2D6 polymorphism between Spaniards and other white subjects. The frequencies for NAT-2 mutations were different in Spaniards compared with Hispanics. About 12% of the subjects studied were incorrectly genotyped by the PCR test. Further studies involving restriction mapping of PCR products revealed the occurrence of at least five NAT-2 mutations that, alone or combined, were present in eight allelic variants of the NAT-2 gene. The allele frequencies were as follows: wild type, 25.3%; 341C + 481T + 803G, 32.9%; 341C + 481T, 6.3%; 282T + 590A, 24.9%; 282T, 3.5%; 590A, 1.6%; 803G, 4.1%; and 857A, 1.4%. The prevalence of the poor acetylator genotype among Spaniards is 53%.

Adolescent↗

Comparison of P+-active and -inactive pro-1 homologues from human nasopharyngeal carcinoma cells.

Eleven pro-1 homologous clones from human nasopharyngeal carcinoma cell line CNE2 were studied with respect to their ability to transfer sensitivity to tumor promoter-induced neoplastic transformation (P+ activity), their molecular structure, and their homology to both mouse pro-1 and each other. Restriction mapping and Southern analysis of CNE2 pro-1 homologous clones revealed three structural classes, all of which showed P+ activity. The approximate limits of mouse pro-1 hybridizing sequences within CNE2 clones from each structural class were identified, and some of these minimum homologous sequences were tested for P+ activity by transfection into P- cells. For all classes, a strong association between P+ activity and pro-1 homology was observed. This finding implies that, for CNE2 clones to be P+-active, structural homology to mouse pro-1 is required. The minimum P+-active sequence thus far identified was a 2.6-kbp EcoRI-SstI fragment. One clone was inactive, even though it was indistinguishable from active clones of the same class by restriction mapping, Southern analysis, and electron microscope examination of heteroduplexes formed by an active and an inactive clone. This raises the possibility that discrete changes, involving a few nucleotides rather than gross rearrangement, may determine the P+ activation of these pro-1-homologous sequences.

Blotting, Southern↗

Construction and expression of hybrid plasmids containing Escherichia coli K-12 uxu genes.

The three genes of the Escherichia coli K-12 uxu region (uxu operon and regulatory gene) were isolated on a ColE1-uxu hybrid plasmid from the bank of Clarke and Carbon, and a restriction map of this region was established. In vitro recombination techniques were used to subclone the uxu restriction fragments into the plasmid vector pBR322 or pBR325. The various chimeric plasmids obtained were analyzed by restriction mapping and characterized genetically by introducing them in uxu mutant or wild-type strains. Differential rates of synthesis of the enzymes coded for by the uxu region were measured in the plasmid-containing strains; amplification of the products of the cloned genes was up to 40-fold the level found in haploid strains. The enzymes coded for by uxuA and uxuB were synthesized in vitro in a coupled transcription-translation system, confirming the results of the cloning experiments. The restriction analysis also suggests that the transcriptional direction of the uxu operon is from uxuA to uxuB and that the order of the loci in this region is: uxuR (regulatory gene), uxuB, uxuA, uxuAp (promoter), uxuAo (operator).

Cloning, Molecular↗

Physical mapping of the virion and the prophage DNAs of a temperate Lactobacillus phage phi FSW.

We analysed the physical structure of the DNA of phi FSW, which is a temperate phage of Lactobacillus casei S-1. A circular restriction map of the virion DNA has been constructed with three restriction endonucleases, BamHI, SalI and XhoI. Other data indicated that the phage genome was circularly permuted. In lysogens, the DNA of the prophage was found to be linearized at a specific site and integrated into a specific locus of the host genome, with the same orientation in each case, as evidenced by Southern filter hybridization. We compared the physical structure of phi FSW with its three virulent mutants. One of them had a restriction map indistinguishable from that of phi FSW and two of them contained host-derived DNA sequence(s) in a specific region of the phi FSW genome (V-region). The prophage integration site was mapped on a different segment of the phage genome to the V-region. Derivation of virulent mutants from phi FSW is discussed in relation to the physical structure of the phage genome.

Bacteriophages↗

Minimal intraspecific variation in the sequence of the transcribed spacer regions of the ribosomal DNA of lake trout (Salvelinus namaycush).

Intraspecific variation in the sequence of the transcribed spacer regions of the ribosomal DNA (rDNA) in lake trout was examined by restriction mapping and sequencing of these regions amplified by the polymerase chain reaction. The length of the first internal transcribed spacer region (ITS-1) was 566 bases and the second internal transcribed spacer region (ITS-2) was 368 bases in lake trout. When the 1.4-kb region including the ITS-1, the 5.8S coding region, and the ITS-2 was amplified from 12 individuals from four populations and digested with eight different enzymes only one intraindividual polymorphism was found that occurred in each population. When the amplified ITS-1 region was sequenced from an additional 10 individuals from five populations, no interindividual variation was found in the sequence. A 6-kb portion of the rDNA repeat unit including 1.6 kb of the 18S coding region, the 5' external spacer region (5' ETS), and part of the adjacent intergenic spacer was cloned and a restriction map was prepared for these regions in lake trout. No intraspecific variation was found in the region adjacent to the 18S rDNA, which includes the 5' ETS, although intraspecific and intraindividual length variation was found in the intergenic spacer region 3-6 kb from the 18S. Sequencing of a 609-b segment of the 5' ETS adjacent to the 18S coding region revealed the presence of two 41-b repeats. The 198-b sequence between the repeats had some similarity to the 18S coding region of other fishes. Primers were designed for amplification of 559 b of the 5' ETS using the polymerase chain reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The use of transposon insertion zdc-235::Tn10 (min 32) to clone and delete DNA from the terminus region of Escherichia coli.

Transposon zdc-235::Tn10 is inserted at min 32 on the genetic map of Escherichia coli, and we have used this transposon to clone 14 kb of DNA that flanks this insertion. The site of insertion of the transposon, and the restriction map of the cloned DNA, correspond well with the predictions of the Bouché restriction map for the terminus region (Bouché 1982). The zdc-235::Tn10 insertion, along with the zdd-230::Tn9 insertion, was used to obtain deletions of the region that has been cloned. Strains lacking a minimum of 14 kb, and more likely a minimum of 40 kb of DNA, showed no alteration of growth or cell morphology.

Chromosome Mapping↗

The ovalbumin gene: structural sequences in native chicken DNA are not contiguous.

The sequence organization of the structural ovalbumin gene and flanking sequences in native chicken DNA was studied by restriction mapping and filter hybridization using a nick-translated probe generated from pOV230, a recombinant plasmid that contains a full-length ovalbumin DNA synthesized from ovalbumin mRNA. The structural sequences of the ovalbumin gene in native chicken DNA were found to be noncontiguous because at least two restriction endonucleases that do not cut the structural sequence do cleave the natural gene into multiple fragments by cleaving within nonstructural sequences interspersed between the structural sequences. The observation that all ovalbumin DNA-containing sequences were contained within a single DNA fragment generated by BamHI digestion of total chicken DNA has allowed us to construct an inclusive restriction map of the natural ovalbumin gene which contains at least two "insert regions." These regions may be further subdivided into alternating structural and insert sequences. Both insert regions were located within the peptide-coding regions of the gene and the sizes of these insert regions were estimated to be approximately 1.0 and 1.5 kilobase pairs, respectively.

Animals↗