TT virus (TTV) has a remarkable genetic heterogeneity. To study TTV evolution, phylogenetic analyses were performed on 739 DNA sequences mapping in the N22 region of ORF1. Analysis of neighbor-joining consensus trees shows significant differences between DNA and protein phylogeny. Median joining networks phylogenetic clustering indicates that DNA sequence analysis is biased by homoplasy (i.e., genetic variability not originated by descent), indicative of either hypermutation or recombination. Statistical analysis shows that the significant excess of homoplasy is due to frequent recombination among closely related strains. Recombination events imply that the transmission of TTV is not clonal and provide the necessary basis to explain (i) the high degree of genetic divergence between TTV isolates, (ii) the lack of population structure on a world scale, and (iii) the number of highly divergent strains that seems typical of this virus. We show that recombination phenomena can be detected by phylogenetic analyses in very short sequences when a sufficiently large data set is available.

Detecting recombination in TT virus: a phylogenetic approach

ROTOLA, Antonella;CASELLI, Elisabetta;BERTORELLE, Giorgio;DI LUCA, Dario
2002

Abstract

TT virus (TTV) has a remarkable genetic heterogeneity. To study TTV evolution, phylogenetic analyses were performed on 739 DNA sequences mapping in the N22 region of ORF1. Analysis of neighbor-joining consensus trees shows significant differences between DNA and protein phylogeny. Median joining networks phylogenetic clustering indicates that DNA sequence analysis is biased by homoplasy (i.e., genetic variability not originated by descent), indicative of either hypermutation or recombination. Statistical analysis shows that the significant excess of homoplasy is due to frequent recombination among closely related strains. Recombination events imply that the transmission of TTV is not clonal and provide the necessary basis to explain (i) the high degree of genetic divergence between TTV isolates, (ii) the lack of population structure on a world scale, and (iii) the number of highly divergent strains that seems typical of this virus. We show that recombination phenomena can be detected by phylogenetic analyses in very short sequences when a sufficiently large data set is available.
2002
Manni, F; Rotola, Antonella; Caselli, Elisabetta; Bertorelle, Giorgio; DI LUCA, Dario
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1198062
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact