P1 phage
Encyclopedia
P1 is a temperate bacteriophage
(phage). The P1 phage can be used to create the P1-derived artificial chromosome
cloning vector
.
l cell
they infect in two different ways. In lysogeny, P1 can exist within a bacterial cell as a circular DNA in that it exists by replicating
as if it were a plasmid
and does not cause cell death. Alternatively, in its lytic
phase, P1 can promote cell lysis
during growth resulting in host cell death. During lysogeny new phage particles are not produced. In contrast, during lytic growth many new phage particles are assembled and released from the cell. By alternating between these two modes of infection, P1 can survive during extreme nutritional conditions that may be imposed upon the bacterial host in which it exists.
A unique feature of phage P1 is that during lysogeny its genome is not incorporated into the bacterial chromosome as is commonly observed during lysogeny of other bacteriophage. Instead, P1 exists independently within the bacterial cell, much like a plasmid
would. P1 replicates as a 90 kilobase
(kb) plasmid in the lysogenic state and is partitioned equally into two new daughter cells during normal cell division
.
P1 encodes a site-specific recombinase, Cre, that is widely used to promote cell-specific or time-specific DNA recombination via flanking loxP sites
Bacteriophage
A bacteriophage is any one of a number of viruses that infect bacteria. They do this by injecting genetic material, which they carry enclosed in an outer protein capsid...
(phage). The P1 phage can be used to create the P1-derived artificial chromosome
P1-derived artificial chromosome
The P1-derived artificial chromosome are DNA constructs that are derived from the DNA of P1 bacteriophage. They can carry large amounts of other sequences for a variety of bioengineering purposes...
cloning vector
Cloning vector
A cloning vector is a small piece of DNA into which a foreign DNA fragment can be inserted. The insertion of the fragment into the cloning vector is carried out by treating the vehicle and the foreign DNA with a restriction enzyme that creates the same overhang, then ligating the fragments...
.
Life cycle
Temperate phage, such as P1, have the ability to exist within the bacteriaBacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
they infect in two different ways. In lysogeny, P1 can exist within a bacterial cell as a circular DNA in that it exists by replicating
DNA replication
DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...
as if it were a plasmid
Plasmid
In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...
and does not cause cell death. Alternatively, in its lytic
Lytic cycle
The lytic cycle is one of the two cycles of viral reproduction, the other being the lysogenic cycle. The lytic cycle is typically considered the main method of viral replication, since it results in the destruction of the infected cell...
phase, P1 can promote cell lysis
Lysis
Lysis refers to the breaking down of a cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a "lysate"....
during growth resulting in host cell death. During lysogeny new phage particles are not produced. In contrast, during lytic growth many new phage particles are assembled and released from the cell. By alternating between these two modes of infection, P1 can survive during extreme nutritional conditions that may be imposed upon the bacterial host in which it exists.
A unique feature of phage P1 is that during lysogeny its genome is not incorporated into the bacterial chromosome as is commonly observed during lysogeny of other bacteriophage. Instead, P1 exists independently within the bacterial cell, much like a plasmid
Plasmid
In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...
would. P1 replicates as a 90 kilobase
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
(kb) plasmid in the lysogenic state and is partitioned equally into two new daughter cells during normal cell division
Cell division
Cell division is the process by which a parent cell divides into two or more daughter cells . Cell division is usually a small segment of a larger cell cycle. This type of cell division in eukaryotes is known as mitosis, and leaves the daughter cell capable of dividing again. The corresponding sort...
.
P1 encodes a site-specific recombinase, Cre, that is widely used to promote cell-specific or time-specific DNA recombination via flanking loxP sites