Table 4.
Comparison of structural, biological, genomic, and functional properties of filamentous phages to that of tailed phages
| Property | Character | Filamentous phage | Tailed phages |
|---|---|---|---|
| Classification |
Order Family |
Not assigned Inoviridae, Plectrovirus |
Caudovirales
Myoviridae, Podoviridae, Siphoviridae |
| Morphology | Shape | Long cylindrical | Diverse shape (vary in tail length and type) |
| Segmentation | Nonsegmented body | Generally segmented body (head, collar, tail, etc.) | |
| Genome | Genome size respect to body length | Smaller genome size as compared to body length (almost double; 3–9.5 kb) | High genome size |
| Host | Host | Infect F+ bacteria only | No preference for F+ or F − |
| Receptor | Receptor | Pilus of the male bacteria | Receptor present on the cell surface |
| No. of receptor | Limited numbers (2–4 per cell) | Many (up to few hundreds per host cell) | |
| Adsorption rate | Adsorption rate constant = 3 × 10−11 cm3/min | Adsorption rate constant = 2.4 × 10−9 cm3/min | |
| Infection | Nature | Chronic | Lytic, Temperate |
| Life cycle | Type | 3 types (episomal, constitutively replicating lysogen and inducible lysogen) | 2 types (lytic and lysogenic) |
| Progeny release | Lysis | Does not kill its host | Kills the host |
| Progeny release | Progeny released throughout the life span of the host | Progeny released once in host's life | |
| Detection | Plaque formation | Absent or turbid (in some cases) | Clear, turbid or centered |
| Observation on plate assay | Difficult | Easy | |
| Electron#x2010;microscopic assay | Generally neglected as debris or pili of bacteria because of its shape and size | Quite easy to distinguish due to characteristics shape and size |