Laboratory of Molecular Biology and Group for Higher Education -
Tetsuro YONESAKI - Assistant Professor - Yuichi OTSUKA Natural
Science Main Building, Toyonaka Campus Bacteriophage (Phage)
infecting prokaryote occupies the largest biomass on the Earth.
Prokaryote corresponds to the lowest level of a food chain and
because phage strongly affects a density of bacterial cells, it
has an important role in the ecosystem of the Earth. Prokaryote
has changed its outer surface to escape from phage-infection or
has developed mechanisms such as restriction enzymes or CRISPR
to interfere with phage growth. On the other hand, phage has
developed mechanisms to overcome the anti-phage mechanisms.
Accordingly, phage and prokaryote are in the process of
coevolution, in which a respective tactics has a role in
evolution of the other. Toxin-antitoxin as an anti-phage
mechanism Prokaryote has TA (toxin-antitoxin) systems to respond
to various stresses. In general, toxins are stable and
antitoxins are unstable. Accordingly, when