plasmid
Học thuậtThân thiện
Definition
Noun A small, circular, extrachromosomal DNA molecule found in bacteria and some other microscopic organisms. Plasmids are physically separate from chromosomal DNA and can replicate independently.
Usage
Plasmids are key tools in genetic engineering and biotechnology. They are used to carry and introduce foreign genes into host organisms. In nature, they often carry genes that provide a selective advantage, such as antibiotic resistance.
Examples
- The scientist inserted the gene into a plasmid for bacterial transformation.
- Bacterial plasmids can be exchanged between cells through a process called conjugation.
- This antibiotic resistance is encoded on a mobile plasmid.
Advanced Usage
- Plasmid copy number: Refers to the number of copies of a plasmid present in a single cell. This is a critical factor in biotechnology for controlling gene expression levels.
- Plasmid incompatibility: A phenomenon where two different plasmids cannot coexist stably in the same bacterial cell line over multiple generations.
- Shuttle plasmid/vector: A plasmid engineered to replicate in the cells of two different species (e.g., and yeast), facilitating cloning and analysis.
Variants and Related Words
- Plasmidic (adjective): Pertaining to or of the nature of a plasmid.
- The plasmidic DNA was isolated for analysis.
- Plasmidome (noun): The total collection of plasmids in a particular environment or organism.
Synonyms
- Vector (in molecular biology): A DNA molecule used as a vehicle to artificially carry genetic material into another cell.
- Extrachromosomal element: A broader term for any genetic material that exists and replicates independently of the chromosomes.
Related Phrases and Terms
- Plasmid preparation: The laboratory process of extracting and purifying plasmid DNA from bacterial cultures.
- Plasmid maintenance: The mechanisms that ensure a plasmid is stably inherited during cell division.
Noun
- a small cellular inclusion consisting of a ring of DNA that is not in a chromosome but is capable of autonomous replication