Virus Genes

, Volume 11, Issue 2, pp 285–297

Evolution of T4-related phages


    • The Evergreen State College
  • Ketevan Gachechiladze
    • Bacteriophage Institute
  • Alexandr Poglazov
    • The Evergreen State College
    • Ivanovsky Inst. of Virology
  • Elena Marusich
    • The Evergreen State College
    • Ivanovsky Inst. of Virology
  • Mikhail Shneider
    • Ivanovsky Inst. of Virology
  • Pia Aronsson
    • The Evergreen State College
  • Alberto Napuli
    • The Evergreen State College
  • Darlene Porter
    • The Evergreen State College
  • Vadim Mesyanzhinov
    • Ivanovsky Inst. of Virology
    • Bach Institute of Biochemistry
Part B: Molecular Processes Involved In The Evolution Of RNA And DNA Viruses

DOI: 10.1007/BF01728666

Cite this article as:
Kutter, E., Gachechiladze, K., Poglazov, A. et al. Virus Genes (1995) 11: 285. doi:10.1007/BF01728666


Much progress has been made in understanding T-even phage biology in the last 50 years. We now know the entire sequence of T4, encoding nearly 300 genes, only 69 of which have been shown to be essential under standard laboratory conditions; no specific function is yet known for about 140 of them. The origin of most phage genes is unclear, and only 42 genes in T4 have significant similarity to anything currently included in GenBank. Comparative analysis of related phages is now being used to gain insight into both the evolutionary origins and interrelationships of these phage genes, and the functions of their protein products. The genomes of phages isolated from Tbilisi hospitals, Long Island sewage plants, the Denver zoo, and Khabarovsk show basic similarity. However, these phages show substantial insertions and deletions in a number of regions relative to each other, and closer investigation of specific sequences often reveals much more complex relationships. There are only a few cases in T4-related phages in which there is evidence for evolution through DNA duplication. These include the fibrous products of genes 12, 34, and 37; head proteins gp23 and gp24; and the Alt enzyme and its downstream neighbors. T4 also contains 13 apparent relatives of group I and group II intron homing endonucleases. Distal portions of the tail fibers of various T-even phages contain segments closely related to tail-fiber regions of other DNA coliphages, such as Mu, P1, P2, and lambda. Horizontal gene transfer clearly emerges as a major factor in the evolution of at least the tail-fiber regions, where site-specific recombination probably is involved in the exchange of host-range determinants.

Key words

T-even phageT4 phageevolutionDNA duplicationhorizontal gene transfer

Copyright information

© Kluwer Academic Publishers 1996