The key difference between lambda phage and M13 phage is that lambda phage is a head to tail bacteriophage that has a linear double-stranded genome while M13 phage is a filamentous bacteriophage that has a circular single-stranded genome.
Viruses are infectious agents. They infect plants, animals, fungi, and bacteria. Bacteriophages are bacterial viruses. They specifically infect bacterial cells. In molecular biology, bacteriophages are used as gene delivery vehicles for eukaryotes. Lambda phage and M13 phage are the most studied and exploited phages among different bacteriophages. They do not show tropism for eukaryotic cells. Furthermore, they show stability in harsh conditions. They are also easy to manipulate and mass production.
CONTENTS
1. Overview and Key Difference
2. What is Lambda Phage
3. What is M13 Phage
4. Similarities – Lambda Phage and M13 Phage
5. Lambda Phage vs M13 Phage in Tabular Form
6. Summary – Lambda Phage vs M13 Phage
What is Lambda Phage?
Lambda phage is a bacteriophage that infects Eschechia coli. Other names of this virus are Escherichia phage lambda, coliphage lambda and Escherichia virus lambda. It is a head to tailed bacteriophage. It has a linear double-stranded genome. Each end of the genome is a 12 bp long overhang. The genome size of this virus is about 48 kb, and the diameter of the icosahedral protein capsid is around 55 nm. In addition, the length of the fibrous tail of this virus is around 145 nm. This virus was discovered by Esther Lederberg in 1950. It is a temperate virus. It can undergo both lytic and lysogenic cycles. During the lysogenic mode, lambda phage exists in the prophage without harming the host bacterium.
Figure 01: Lambda Phage
Lambda phage is useful as a vector in gene delivery for eukaryotic cells. It is used as a cloning vector in genomic library construction. But lambda phage vector can only deliver a size of 35–50 kb of DNA. This is one of the limitations of this virus as a vector.
What is M13 Phage?
M13 phage is a bacteriophage that is a member of the family filamentous bacteriophage. It infects E. coli. M13 phage has a single-stranded positive-sense circular genome. Its genome size is about 6.4 kb, and it codes for ten genes. It is a simple genome.
Figure 02: M13 Phage
The capsid of the M13 phage can be extended by adding protein subunits further. The capsid is helical in shape. Similar to lambda phage, M13 is also a useful cloning vector. It is one of the first vectors developed for molecular cloning. The size of the DNA insert is 12 kb for M13.
What are the Similarities Between Lambda Phage and M13 Phage?
- Both Lambda phage and M13 phage are bacteriophages or bacterial viruses that specifically infect bacteria.
- Their host bacterium is Escherichia coli.
- They are cloning vectors commonly used in recombinant DNA technology and genetic engineering.
- They act as gene delivery vehicles in molecular biology.
- Therefore, both these phages were among the first vectors developed for molecular cloning.
What is the Difference Between Lambda Phage and M13 Phage?
Lambda phage is a head to tailed bacteriophage that has a linear double-stranded genome, while M13 phage is a filamentous bacteriophage that has a single-stranded circular genome. So, this is the key difference between lambda phage and M13 phage. The size of the lambda phage genome is about 48kb, while the size of the M13 genome is about 6.4 kb.
The below infographic lists the differences between lambda phage and M13 phage in tabular form for side by side comparison.
Summary – Lambda Phage vs M13 Phage
Lambda phage is a head to tailed bacteriophage. It possesses a linear double-stranded genome. In contrast, M13 phage is a filamentous bacteriophage and possesses a circular single-stranded genome. Thus, this is the difference between lambda phage and M13 phage. Both bacteriophages infect E. coli. Both these phages are widely used as cloning vectors.