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Titolo:
The role of recombination and mutation in 16S-23S rDNA spacer rearrangements
Autore:
Gurtler, V;
Indirizzi:
Austin & Repatriat Med Ctr, Dept Microbiol, Heidelberg, Vic 3084, Australia Austin & Repatriat Med Ctr Heidelberg Vic Australia 3084 3084, Australia
Titolo Testata:
GENE
fascicolo: 1, volume: 238, anno: 1999,
pagine: 241 - 252
SICI:
0378-1119(19990930)238:1<241:TRORAM>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
COMPLETE GENOME SEQUENCE; RIBOSOMAL-RNA GENES; ESCHERICHIA-COLI; TRANSCRIPTION UNITS; PCR-AMPLIFICATION; CLOSTRIDIUM-DIFFICILE; BORRELIA-BURGDORFERI; SECONDARY STRUCTURES; BACILLUS-SUBTILIS; REGIONS;
Keywords:
concerted evolution; homologous recombination; maximum likelihood; phylogenomic analysis; rrn operon;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
62
Recensione:
Indirizzi per estratti:
Indirizzo: Gurtler, V Austin & Repatriat Med Ctr, Dept Microbiol, Austin Campus,Studley Rd, Heidelberg, Vic 3084, Australia Austin & Repatriat Med Ctr Austin Campus,Studley Rd Heidelberg Vic Australia 3084
Citazione:
V. Gurtler, "The role of recombination and mutation in 16S-23S rDNA spacer rearrangements", GENE, 238(1), 1999, pp. 241-252

Abstract

The intragenomic heterogeneity of the bacterial intergenic (16S-23S rDNA) spacer region (ISR) was analysed from the following species in which sequences for the complete rRNA operon (rrn) set have been determined (rrn number): Enterococcus faecalis (6) and E. faecium (6), Bacillus subtilis (10), Staphylococcus aureus (9), Vibrio cholerae (4), Haemophilus influenzae (6) and Escherichia coli (7). It was found that some spacer sequence blocks were highly conserved between operons of a genome, whereas the presence of others was variable. When these variations were analysed using the program PLATOand partial likelihood phylogenies determined by DNAml for each operon set, three regions showed significant (Z>3.3) spatial variation [Region I was 78-184 nt long (2.1<Z<49.4), Region II was 10-60 nt long (3.7<Z<23)] and Region III was 6 nt long (3.4<Z>4.4) possibly due to recombination or selection. Within Region I, there was sequence block variation in all operon sets [some operons contained tRNA genes (tRNA(ala), tRNA(ile) or tRNA(glu)), whereas others had sequence blocks such as VS2 (S. aureus) or rsl (E. coli)]. Q Analysis of the ISR sequence from E. faecalis and E. faecium showed that there was more interspecies than intraspecies variation (both in DNA sequence and in the presence or absence of blocks). Dot matrix analysis of the sequence blocks in the nine rrn ISRs from S. aureus showed that there was significant homology between VS2 and VS5/VS6. Furthermore, repeat motifs with only A or T were present in higher copy numbers in VS5/VS6 than in VS2. Since these sequence blocks (VS2 and VS5-VS6) are related, intragenic evolution resulting in AT expansion may have occurred between these two regions. A model is proposed that postulates a role for recombination and AT-expansionin intra-genomic ISR variations. This process may represent a general mechanism of concerted evolution for bacterial ISR rearrangements. (C) 1999 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 15:57:36