scholarly journals The evolutionary history of krill inferred from nuclear large subunit rDNA sequence analysis

2001 ◽  
Vol 73 (2) ◽  
pp. 199-212 ◽  
Author(s):  
SIMON N. JARMAN
Keyword(s):  
Sequence Analysis ◽  
Evolutionary History ◽  
Large Subunit ◽  
Rdna Sequence ◽  
History Of ◽  
Large Subunit Rdna

scholarly journals A New Borrelia Species Defined by Multilocus Sequence Analysis of Housekeeping Genes

2009 ◽  
Vol 75 (16) ◽  
pp. 5410-5416 ◽  
Author(s):  
Gabriele Margos ◽  
Stephanie A. Vollmer ◽  
Muriel Cornet ◽  
Martine Garnier ◽  
Volker Fingerle ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Lyme Borreliosis ◽  
Phylogenetic Trees ◽  
Evolutionary History ◽  
Housekeeping Genes ◽  
Multilocus Sequence Analysis ◽  
Species Status ◽  
Borrelia Garinii ◽  
Analysis Scheme ◽  
History Of

ABSTRACT Analysis of Lyme borreliosis (LB) spirochetes, using a novel multilocus sequence analysis scheme, revealed that OspA serotype 4 strains (a rodent-associated ecotype) of Borrelia garinii were sufficiently genetically distinct from bird-associated B. garinii strains to deserve species status. We suggest that OspA serotype 4 strains be raised to species status and named Borrelia bavariensis sp. nov. The rooted phylogenetic trees provide novel insights into the evolutionary history of LB spirochetes.

scholarly journals The Large Subunit rDNA Sequence of Plasmodiophora brassicae Does not Contain Intra-species Polymorphism

Protist ◽  
2016 ◽  
Vol 167 (6) ◽  
pp. 544-554 ◽  
Author(s):  
Arne Schwelm ◽  
Cédric Berney ◽  
Christina Dixelius ◽  
David Bass ◽  
Sigrid Neuhauser
Keyword(s):  
Plasmodiophora Brassicae ◽  
Large Subunit ◽  
Rdna Sequence ◽  
Large Subunit Rdna

scholarly journals Telomeric location of Giardia rDNA genes.

1991 ◽  
Vol 11 (6) ◽  
pp. 3326-3330 ◽  
Author(s):  
R D Adam ◽  
T E Nash ◽  
T E Wellems
Keyword(s):  
Tandem Repeats ◽  
Dna Analysis ◽  
Large Subunit ◽  
Intergenic Spacer ◽  
Rdna Sequence ◽  
Rrna Genes ◽  
Rdna Genes ◽  
Pulsed Field ◽  
Large Subunit Rdna ◽  
A Site

Giardia lamblia telomeres have been isolated from a library enriched for repaired chromosome ends by (i) screening with a Plasmodium falciparum telomere and (ii) differential hybridization with Bal 31-digested and total G. lamblia DNA. Analysis of three clones isolated by this strategy has identified multiple tandem repeats of the 5-mer TAGGG. An oligonucleotide containing these repeats recognizes Bal 31-sensitive bands in Southern hybridizations and detects all G. lamblia chromosomes in pulsed-field gel electrophoresis separations. An abrupt transition from the G. lamblia rDNA sequence to telomeric repeats has been found in all three clones. In two of the clones the transition occurs at the same site, near the beginning of the large subunit rDNA sequence. In the third clone the transition occurs at a site in the intergenic spacer sequence between the rDNA genes. Hybridization of an rDNA probe to a pulsed-field separation of G. lamblia chromosomes indicates that rDNA genes are present on several chromosomes but vary in location from isolate to isolate. These results suggest that rRNA genes are clustered at telomeric locations in G. lamblia and that these clusters are mobile.

scholarly journals Inferring the Evolutionary History of Vibrios by Means of Multilocus Sequence Analysis

2007 ◽  
Vol 189 (21) ◽  
pp. 7932-7936 ◽  
Author(s):  
Tomoo Sawabe ◽  
Kumiko Kita-Tsukamoto ◽  
Fabiano L. Thompson
Keyword(s):  
Sequence Analysis ◽  
Evolutionary History ◽  
Gene Sequence ◽  
Sequence Data ◽  
Sequence Similarity ◽  
Housekeeping Genes ◽  
Amino Acid Identity ◽  
Multilocus Sequence Analysis ◽  
Protein Coding ◽  
History Of

ABSTRACT We performed the first broad study aiming at the reconstruction of the evolutionary history of vibrios by means of multilocus sequence analysis of nine genes. Overall, 14 distinct clades were recognized using the SplitsTree decomposition method. Some of these clades may correspond to families, e.g., the clades Salinivibrio and Photobacteria, while other clades, e.g., Splendidus and Harveyi, correspond to genera. The common ancestor of all vibrios was estimated to have been present 600 million years ago. We can define species of vibrios as groups of strains that share >95% gene sequence similarity and >99.4% amino acid identity based on the eight protein-coding housekeeping genes. The gene sequence data were used to refine the standard online electronic taxonomic scheme for vibrios (http://www.taxvibrio.lncc.br ).

scholarly journals Evolutionary History of hrgA, Which Replaces the Restriction Gene hpyIIIR in the hpyIII Locus of Helicobacter pylori

2003 ◽  
Vol 185 (1) ◽  
pp. 295-301 ◽  
Author(s):  
T. Ando ◽  
R. A. Aras ◽  
K. Kusugami ◽  
M. J. Blaser ◽  
T. M. Wassenaar
Keyword(s):  
Helicobacter Pylori ◽  
Sequence Analysis ◽  
Homologous Recombination ◽  
Restriction Endonuclease ◽  
Evolutionary History ◽  
Chromosomal Dna ◽  
History Of ◽  
Flanking Sequences ◽  
H Pylori

ABSTRACT A recently identified Helicobacter pylori gene, hrgA, was previously reported to be present in 70 (33%) of 208 strains examined (T. Ando, T. M. Wassenaar, R. M. Peek, R. A. Aras, A. I. Tschumi, L.-J. Van Doorn, K. Kusugami, and M. J. Blaser, Cancer Res. 62:2385-2389, 2002). Sequence analysis of nine such strains indicated that in each strain hrgA replaced hpyIIIR, which encodes a restriction endonuclease and which, together with the gene for its cognate methyltransferase, constitutes the hpyIII locus. As a consequence of either the hrgA insertion or independent mutations, hpyIIIM function was lost in 11 (5%) of the 208 strains examined, rendering chromosomal DNA sensitive to MboI digestion. The evolutionary history of the locus containing either hpyIII or hrgA was reconstructed. By homologous recombination involving flanking sequences, hrgA and hpyIIIR can replace one another in the hpyIII locus, and there is simultaneous replacement of several flanking genes. These findings, combined with the hpyIM/iceA2 locus discovered previously, suggest that the two most strongly conserved methylase genes of H. pylori, hpyIIIM and hpyIM, are both preceded by alternative genes that compete for presence at their loci.

Telomeric location of Giardia rDNA genes

1991 ◽  
Vol 11 (6) ◽  
pp. 3326-3330
Author(s):  
R D Adam ◽  
T E Nash ◽  
T E Wellems
Keyword(s):  
Tandem Repeats ◽  
Dna Analysis ◽  
Large Subunit ◽  
Intergenic Spacer ◽  
Rdna Sequence ◽  
Rrna Genes ◽  
Rdna Genes ◽  
Pulsed Field ◽  
Large Subunit Rdna ◽  
A Site

Giardia lamblia telomeres have been isolated from a library enriched for repaired chromosome ends by (i) screening with a Plasmodium falciparum telomere and (ii) differential hybridization with Bal 31-digested and total G. lamblia DNA. Analysis of three clones isolated by this strategy has identified multiple tandem repeats of the 5-mer TAGGG. An oligonucleotide containing these repeats recognizes Bal 31-sensitive bands in Southern hybridizations and detects all G. lamblia chromosomes in pulsed-field gel electrophoresis separations. An abrupt transition from the G. lamblia rDNA sequence to telomeric repeats has been found in all three clones. In two of the clones the transition occurs at the same site, near the beginning of the large subunit rDNA sequence. In the third clone the transition occurs at a site in the intergenic spacer sequence between the rDNA genes. Hybridization of an rDNA probe to a pulsed-field separation of G. lamblia chromosomes indicates that rDNA genes are present on several chromosomes but vary in location from isolate to isolate. These results suggest that rRNA genes are clustered at telomeric locations in G. lamblia and that these clusters are mobile.

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