MoBio Bacteriophages Chapter 1

Bacteriophages are viruses infecting bacteria. Their genetic material can be DNA or RNA; single-stranded (ss) or double-stranded (ds). The following are a few examples:

1. dsDNA phages with contractile tails, such as T4.

2. dsDNA phages with long flexible tails, such as λ.

3. dsDNA phages with stubby tails, such as p22.

4. ssDNA phages, such as phi X 174.

5. ssRNA phages, such as MS2.

Image

Figure 1-F. A 3D render of a T4 type bacteriophage landing on a bacterium to inject genetic material [Source: Wikipedia].

The life cycle of a bacteriophage may be lytic, lysogenic, or both. An important example is λ phages which can have either lytic or lysogenic cycle, depending on the environment (more info).