 |
| Site Index |
|
|
|
||||
About UsTbilisiPhage ResearchPhage TherapyPhageBiotics Funds
|
T4 in the Natural World: Life after Log from a Phage Perspective |
|||
|
Elizabeth Kutter, Lex Ball, Barbara Anderson, Pia Lipincott, Chelsea Thomas, Elizabeth Thomas. Evergreen State College, Olympia, WA Bacteriophage T4 has been studied intensely for over 50 years, but virtually all of the published work has been done with bacteria growing exponentially in rich media. Recently, a major emphasis in bacterial work has been placed on developing an understanding of microbial physiology under the "feast-and-famine" situations much more commonly encountered in nature, including in the complex ecosystem of the mammalian gut. We present evidence that the virulent T-even phages have evolved ways to reproduce under these environmental conditions and may well have mechanisms to sense and respond appropriately to their host's physiological state. The common wisdom is that T4 cannot replicate in stationary phase cells, but we find that it can exist in a state we have termed "hibernation" in such cells, able to still make infective centers when nutrients become available. Preliminary gel electrophoresis experiments show that the infected cells can still make most host upshift proteins immediately after adding nutrients, in sharp contrast to the rapid total termination of host transcription and translation seen during infection in stationary phase. The pattern gradually shifts to mainly making phage proteins and a few phage particles. We are exploring the changes in regulatory mechanisms. We suggest that some of the T4 proteins with no known function (over half of the total) may have special roles in adapting to unexplored environmental conditions, such as stationary phase. An exploration of phage interactions with their hosts in such natural conditions is potentially very useful in understanding microbial physiology and is of particular importance as interest grows in the use of bacteriophage as antibiotics. Another important finding in this regard is that T4 does not seem to exchange genes with its microbial hosts. Most of T4's genes have no matches in the databases beyond other phages; among those that do, the most recent divergence seems to have occurred before the differentiation between E. coli and H. Influenzae. |
Bacteriophage |
|||
|
Last Updated: May 29, 2008 All content and images on this site are copyrighted by The Evergreen State College. |
||||
