Examples of recombinant DNA in the following topics:
-
- Many practical applications of recombinant DNA are found in human and veterinary medicine, in agriculture, and in bioengineering.
- Recombinant DNA technology is the latest biochemical analysis that came about to satisfy the need for specific DNA segments.
- Recombinant DNA technology engineers microbial cells for producing foreign proteins, and its success solely depends on the precise reading of equivalent genes made with the help of bacterial cell machinery.
- Recombinant DNA technology, apart from being an important tool of scientific research, has also played a vital role in the diagnosis and treatment of various diseases, especially those belonging to genetic disorders.
- Some of the recent advances made possible by recombinant DNA technology are:
-
- DNA recombination has been used to create gene replacements, deletions, insertions, inversions.
- Subsequently, these fragments are then combined with vector DNA to generate recombinant DNA molecules.
- This will generate a population of organisms in which recombinant DNA molecules are replicated along with the host DNA.
- Thus, both the resulting bacterial population, and the recombinant DNA molecule, are commonly referred to as "clones".
- Strictly speaking, recombinant DNA refers to DNA molecules, while molecular cloning refers to the experimental methods used to assemble them.
-
- Recombinant DNA technology also referred to as molecular cloning is similar to polymerase chain reaction (PCR) in that it permits the replication of a specific DNA sequence.
- To improve the ratio of recombinant to non-recombinant organisms, the cleaved vector may be treated with an enzyme (alkaline phosphatase) that dephosphorylates the vector ends.
- The creation of recombinant DNA is in many ways the simplest step of the molecular cloning process.
- Insertion of the foreign DNA into the beta-galactosidase coding sequence disables the function of the enzyme, so that colonies containing recombinant plasmids remain colorless (white).
- Therefore, recombinant clones are easily identified .
-
- Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms.
- Molecular cloning generally uses DNA sequences from two different organisms: the species that is the source of the DNA to be cloned, and the species that will serve as the living host for replication of the recombinant DNA.
- The creation of recombinant DNA is in many ways the simplest step of the molecular cloning process.
- Whichever method is used, the introduction of recombinant DNA into the chosen host organism is usually a low efficiency process; that is, only a small fraction of the cells will actually take up DNA.
- Explain the methods of obtaining DNA for molecular cloning experiments and the process of creating a recombinant DNA molecule
-
- The isolation of approximately 3000 restriction enzymes has allowed molecular biologists to utilize them in processes such as cloning and the production of recombinant DNA .
- DNA ligase plays a key role in molecular biology processes due to its ability to insert DNA fragments into plasmids.
- The process of DNA ligation is defined as the ability of DNA ligase to covalently link, or ligate, fragments of DNA together.
- In molecular biology -- specifically, during the process of developing recombinant DNA -- DNA ligase can be used to ligate a fragment of DNA into a plasmid vector .
- The most commonly used DNA ligase is derived from the T4 bacteriophage and is referred to as T4 DNA ligase.
-
- In homologous recombination, a type of genetic recombination, nucleotide sequences are exchanged between two similar molecules of DNA.
- Homologous recombination is a type of genetic recombination in which nucleotide sequences are exchanged between two similar or identical molecules of DNA.
- Homologous recombination is a major DNA repair process in bacteria.
- Double-strand DNA breaks in bacteria are repaired by the RecBCD pathway of homologous recombination .
- The RecBCD pathway is the main recombination pathway used in bacteria to repair double-strand breaks in DNA.
-
- There are generally three types of recombination events that can lead to this incorporation of bacterial DNA into the viral DNA, leading to two modes of recombination.
- This may occur in two main ways, recombination and headful packaging.
- This bacterial material may become recombined into another bacterium upon infection.
- When the new DNA is inserted into this recipient cell it can fall to one of three fates: the DNA will be absorbed by the cell and be recycled for spare parts; if the DNA was originally a plasmid, it will recirculate inside the new cell and become a plasmid again; if the new DNA matches with a homologous region of the recipient cell's chromosome, it will exchange DNA material similar to the actions in conjugation.
- This type of recombination is random and the amount recombined depends on the size of the virus being used.
-
- E. coli and plasmid vectors are in common use because they are technically sophisticated, versatile, widely available, and offer rapid growth of recombinant organisms with minimal equipment.
- If the DNA to be cloned is exceptionally large (hundreds of thousands to millions of base pairs), then a bacterial artificial chromosome or yeast artificial chromosome vector is often chosen.
- For example, if the experimentalists wish to harvest a particular protein from the recombinant organism, then an expression vector is chosen that contains appropriate signals for transcription and translation in the desired host organism.
- Alternatively, if replication of the DNA in different species is desired (for example transfer of DNA from bacteria to plants), then a multiple host range vector (also termed shuttle vector) may be selected.
- Whatever combination of host and vector are used, the vector almost always contains four DNA segments that are critically important to its function and experimental utility--(1) an origin of DNA replication is necessary for the vector (and recombinant sequences linked to it) to replicate inside the host organism, (2) one or more unique restriction endonuclease recognition sites that serves as sites where foreign DNA may be introduced, (3) a selectable genetic marker gene that can be used to enable the survival of cells that have taken up vector sequences, and (4) an additional gene that can be used for screening which cells contain foreign DNA.
-
- Bacteriophage Mu is a temperate bacteriophage that uses DNA-based transposition in its lysogenic cycle.
- Mu bacteriophage uses DNA-based transposition to integrate its genome into the genome of the host cell that it is infecting.
- It can then use transposition to initiate its viral DNA replication.
- Once the viral DNA is inserted into the bacteria, the Mu's transposase protein/enzyme in the cell recognizes the recombination sites at the ends of the viral DNA (gix-L and gix-R sites) and binds to them, allowing the process of replicating the viral DNA or embedding it into the host genome.
- Its transposition mechanism is somewhat similar to a homologous recombination.
-
- Bacterial transformation may be referred to as a stable genetic change, brought about by the uptake of naked DNA (DNA without associated cells or proteins).
- Some species, upon cell death, release their DNA to be taken up by other cells; however, transformation works best with DNA from closely-related species.
- The DNA first binds to the surface of the competent cells on a DNA receptor, and passes through the cytoplasmic membrane via DNA translocase.
- The uptake of DNA is generally non-sequence specific, although in some species the presence of specific DNA uptake sequences may facilitate efficient DNA uptake.
- The exogenous DNA is incorporated into the host cell's chromosome via recombination.