The genome of the brown alga Ectocarpus siliculosus contains a series of viral DNA pieces, suggesting an ancient association with large dsDNA viruses

被引:43
作者
Delaroque, Nicolas [1 ]
Boland, Wilhelm [1 ]
机构
[1] Max Planck Inst Chem Okol, D-07745 Jena, Germany
关键词
D O I
10.1186/1471-2148-8-110
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Background: Ectocarpus siliculosus virus-1 (EsV-1) is a lysogenic dsDNA virus belonging to the super family of nucleocytoplasmic large DNA viruses (NCLDV) that infect Ectocarpus siliculosus, a marine filamentous brown alga. Previous studies indicated that the viral genome is integrated into the host DNA. In order to find the integration sites of the viral genome, a genomic library from EsV-1-infected algae was screened using labelled EsV-1 DNA. Several fragments were isolated and some of them were sequenced and analyzed in detail. Results: Analysis revealed that the algal genome is split by a copy of viral sequences that have a high identity to EsV-1 DNA sequences. These fragments are interspersed with DNA repeats, pseudogenes and genes coding for products involved in DNA replication, integration and transposition. Some of these gene products are not encoded by EsV-1 but are present in the genome of other members of the NCLDV family. Further analysis suggests that the Ectocarpus algal genome contains traces of the integration of a large dsDNA viral genome; this genome could be the ancestor of the extant NCLDV genomes. Furthermore, several lines of evidence indicate that the EsV-1 genome might have originated in these viral DNA pieces, implying the existence of a complex integration and recombination system. A protein similar to a new class of tyrosine recombinases might be a key enzyme of this system. Conclusion: Our results support the hypothesis that some dsDNA viruses are monophyletic and evolved principally through genome reduction. Moreover, we hypothesize that phaeoviruses have probably developed an original replication system.
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共 47 条
  • [1] ACHULTZ J, 1998, P NATL ACAD SCI USA, V95, P5857
  • [2] BASIC LOCAL ALIGNMENT SEARCH TOOL
    ALTSCHUL, SF
    GISH, W
    MILLER, W
    MYERS, EW
    LIPMAN, DJ
    [J]. JOURNAL OF MOLECULAR BIOLOGY, 1990, 215 (03) : 403 - 410
  • [3] [Anonymous], 1989, Molecular Cloning
  • [4] What does structure tell us about virus evolution?
    Bamford, DH
    Grimes, JM
    Stuart, DI
    [J]. CURRENT OPINION IN STRUCTURAL BIOLOGY, 2005, 15 (06) : 655 - 663
  • [5] BELL PJ, 2006, J THEOR BIOL
  • [6] Bell PJL, 2001, J MOL EVOL, V53, P251
  • [7] INHERITANCE AND MEIOTIC ELIMINATION OF A VIRUS GENOME IN THE HOST ECTOCARPUS-SILICULOSUS (PHAEOPHYCEAE)
    BRAUTIGAM, M
    KLEIN, M
    KNIPPERS, R
    MULLER, DG
    [J]. JOURNAL OF PHYCOLOGY, 1995, 31 (05) : 823 - 827
  • [8] CAMPO ED, 1997, PHYCOLOGIA, V36, P186
  • [9] Viruses take center stage in cellular evolution
    Claverie, Jean-Michel
    [J]. GENOME BIOLOGY, 2006, 7 (06)
  • [10] Comparisons of two large phaeoviral genomes and evolutionary implications
    Delaroque, N
    Boland, W
    Müller, DG
    Knippers, R
    [J]. JOURNAL OF MOLECULAR EVOLUTION, 2003, 57 (06) : 613 - 622