Dna Heteroduplex
Mostrando 13-24 de 557 artigos, teses e dissertações.
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13. Fate of mismatched base-pair regions in polyoma heteroduplex DNA during infection of mouse cells.
Heteroduplex DNA has been constructed from two variants of polyoma virus that differ genotypically at four distinct sites. The genotypes of the progeny virus derived from infections of mouse cells with single heteroduplexes have been analyzed to determine how the genotypic markers of the parental heteroduplex segregate. Markers that are separated by a length
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14. Formation of heteroduplex DNA during mammalian intrachromosomal gene conversion.
We have studied intrachromosomal gene conversion in mouse Ltk- cells with a substrate designed to provide genetic evidence for heteroduplex DNA. Our recombination substrate consists of two defective chicken thymidine kinase genes arranged so as to favor the selection of gene conversion products. The gene intended to serve as the recipient in gene conversion
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15. Detection of heteroduplex DNA molecules among the products of Saccharomyces cerevisiae meiosis.
We have used denaturant-gel electrophoresis to provide a physical demonstration of heteroduplex DNA in the products of yeast meiosis. We examined heteroduplex formation at arg4-nsp, a G.C----C.G transversion that displays a moderately high level of postmeiotic segregation. Of the two possible arg4-nsp/ARG4 mismatches (G.G and C.C), only C.C was detected in s
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16. The E.coli RuvAB proteins branch migrate Holliday junctions through heterologous DNA sequences in a reaction facilitated by SSB.
During genetic recombination a heteroduplex joint is formed between two homologous DNA molecules. The heteroduplex joint plays an important role in recombination since it accommodates sequence heterogeneities (mismatches, insertions or deletions) that lead to genetic variation. Two Escherichia coli proteins, RuvA and RuvB, promote the formation of heterodupl
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17. Use of homoduplex ribosomal DNA spacer amplification products and heteroduplex cross-hybridization products in the identification of Salmonella serovars.
When the hypervariable 16S-23S intergenic spacer regions found in prokaryotic ribosomal DNA (rDNA) are amplified from conserved adjacent sequences, homoduplex double-stranded DNA structures and heteroduplex structures containing substantial regions of single-stranded DNA are generated. The electrophoretic separation of these structures results in product pro
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18. Gene conversion in Escherichia coli: the recF pathway for resolution of heteroduplex DNA.
The independent repair of mismatched nucleotides present in heteroduplex DNA has been used to explain gene conversion and map expansion after general genetic recombination. We have constructed and purified heteroduplex plasmid DNAs that contain heteroallelic 10-base-pair insertion-deletion mismatches. These DNA substrates are similar in structure to the hete
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19. Recombination and chimeragenesis by in vitro heteroduplex formation and in vivo repair.
We describe a simple method for creating libraries of chimeric DNA sequences derived from homologous parental sequences. A heteroduplex formed in vitro is used to transform bacterial cells where repair of regions of non-identity in the heteroduplex creates a library of new, recombined sequences composed of elements from each parent. Heteroduplex recombinatio
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20. Evidence for Conversion of Heteroduplex Transforming DNAs to Homoduplexes by Recipient Pneumococcal Cells
Heteroduplex molecules of pneumococcal DNA, prepared by cross-annealing resolved complementary strands, have been used as donors in transformation. A number of pairs of genetic markers are situated exclusively in the trans configuration in these heteroduplexes. Insertion of two markers from trans configuration into opposite DNA strands of a recipient genome
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21. Homogenization of Tandemly Repeated Nucleotide Sequences by Distance-Dependent Nucleotide Sequence Conversion
Previous work revealed that recurrent mutations (=mutation occurring more than once) in the tandemly repeated arrays present in nontranscribed spacers (NTS) of ribosomal RNA genes (rDNA) are clustered, i.e., they most frequently occur in repeats with adjacent or alternate distribution. A possible explanation is that the likelihood of heteroduplex formation,
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22. Rapid kinetics of mismatch repair of heteroduplex DNA that is formed during recombination in yeast.
Homothallic switching of yeast mating type (MAT) genes is a highly efficient gene conversion process initiated by a double-strand break. The use of a galactose-inducible HO endonuclease gene has made it possible to analyze the synchronous progression of molecular intermediates during recombination. When MATa switches to MAT alpha, a 3' single-stranded end of
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23. Detection of non-homology-containing heteroduplex molecules.
Heteroduplex DNA molecules which contain both the wild-type and mutant sequences of a deletion nonhomology possess a characteristic electrophoretic mobility in agarose and can be readily separated from both the wild-type and deletion-containing parental homoduplex fragments. Because of the partial single stranded character of these deletion-containing hetero
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24. Timing of molecular events in meiosis in Saccharomyces cerevisiae: stable heteroduplex DNA is formed late in meiotic prophase.
To better understand the means by which chromosomes pair and recombine during meiosis, we have determined the time of appearance of heteroduplex DNA relative to the times of appearance of double-strand DNA breaks and of mature recombined molecules. Site-specific double-strand breaks appeared early in meiosis and were formed and repaired with a timing consist