cloning

(noun)

The production of a cloned embryo by transplanting the nucleus of a somatic cell into an ovum.

Related Terms

Examples of cloning in the following topics:

  • Obtaining DNA

    • When cloning genomic DNA, the DNA to be cloned is extracted from the organism of interest.
    • For cloning of genomic DNA, the DNA to be cloned is extracted from the organism of interest.
    • DNA for cloning experiments may also be obtained from RNA using reverse transcriptase (complementary DNA or cDNA cloning), or in the form of synthetic DNA (artificial gene synthesis). cDNA cloning is usually used to obtain clones representative of the mRNA population of the cells of interest, while synthetic DNA is used to obtain any precise sequence defined by the designer.
    • Although a very large number of host organisms and molecular cloning vectors are used, the great majority of molecular cloning experiments begin with a laboratory strain of the bacterium E. coli (Escherichia coli) and a plasmid cloning vector.
    • Cells harboring the cloning vector will survive when exposed to the antibiotic, while those that have failed to take up cloning vector will die.

  • Hosts for Cloning Vectors

    • The majority of molecular cloning experiments begin with a laboratory strain of the bacterium E. coli (Escherichia coli) as the host.
    • A very large number of host organisms and molecular cloning vectors are in use, but the great majority of molecular cloning experiments begin with a laboratory strain of the bacterium E. coli (Escherichia coli) and a plasmid cloning vector.
    • 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.
    • In practice, however, specialized molecular cloning experiments usually begin with cloning into a bacterial plasmid, followed by subcloning into a specialized vector.

  • Recombinant DNA Technology

    • In standard molecular cloning experiments, the cloning of any DNA fragment essentially involves seven steps:
    • Although a very large number of host organisms and molecular cloning vectors are in use, the great majority of molecular cloning experiments begin with a laboratory strain of the bacterium E. coli (Escherichia coli) and a plasmid cloning vector.
    • For cloning of genomic DNA, the DNA to be cloned is extracted from the organism of interest.
    • Modern bacterial cloning vectors (e.g. pUC19) use the blue-white screening system to distinguish colonies (clones) of transgenic cells from those that contain the parental vector.
    • Therefore, recombinant clones are easily identified .

  • Selection

    • Artificial selection is widely used in the field of microbial genetics, especially molecular cloning.
    • Gene cloning and gene/protein tagging is also common.
    • 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.
    • Molecular cloning methods are central to many contemporary areas of modern biology and medicine.
    • In a conventional molecular cloning experiment, the DNA to be cloned is obtained from an organism of interest.

  • Shuttle Vectors and Expression Vectors

    • Therefore, to make the purification process easy, the cloned gene should have a tag.
    • Cloning vectors, which are very similar to expression vectors, involve the same process of introducing a new gene into a plasmid, but the plasmid is then added into bacteria for replication purposes.
    • In general, DNA vectors that are used in many molecular-biology gene-cloning experiments need not result in the expression of a protein.
    • The pGEX-3x plasmid is a popular cloning vector.
    • Please note the presence of a multiple cloning site, a promoter, a repressor, and a selectable marker.

  • Plasmids as Cloning Vectors

    • Plasmids can be used as cloning vectors, allowing the insertion of exogenous DNA into a bacterial target.
    • All engineered vectors have an origin of replication, a multi-cloning site, and a selectable marker.
    • Modern plasmids generally have many more features, notably a "multiple cloning site"—with nucleotide overhangs for insertion of an insert—and multiple restriction enzyme consensus sites on either side of the insert.
    • The pGEX-3x plasmid is a popular cloning vector.

  • Genetic Analysis

    • PFGE is essential for estimating the sizes of whole genomes/chromosomes prior to sequencing and is necessary for preparing large DNA fragments for large insert DNA cloning and analysis of subsequent clones.
    • DNA cloning is another technique fundamental to molecular biology that requires adaptation in order to be useful in studying DNA at a whole genome scale.
    • There are two main approaches to sequencing microbial genomes – the ordered clone approach and direct shotgun sequencing both require large and small insert genomic DNA libraries in order to be effective.
    • Summarize the techniques used to study genomes: PFGE. ordered clone approach, direct shotgun sequencing and microarray hybridization

  • Clonal Selection of Antibody-Producing Cells

    • Talmage, worked on this model and was the first to name it "clonal selection theory. " Burnet explained immunological memory as the cloning of two types of lymphocyte.
    • B cells exist as clones.
    • The great diversity in immune response comes about due to the up to 109 clones with specificities for recognizing different antigens.
    • Upon encountering its specific antigen, a single B cell, or a clone of cells with shared specificity, divides to produce many B cells.
    • Most of these will never encounter a matching 5) foreign antigen, but those that do are activated and produce 6) many clones of themselves.

  • Vectors for Genomic Cloning and Sequencing

    • Modern plasmids generally have many more features, notably including a "multiple cloning site" which includes nucleotide overhangs for insertion of an insert, and multiple restriction enzyme consensus sites to either side of the insert.
    • The vectors can be extracted from the bacteria, and the multiple cloning sites can be cut by restriction enzymes to excise the hundredfold or thousandfold amplified insert.

  • Detecting Uncultured Microorganisms

    • More specifically, the construction of libraries in bacterial artificial chromosomes (BACs) provided better vectors for molecular cloning.
    • Shotgun sequencing and screens of clone libraries reveal genes present in environmental samples.
    • (A) sampling from habitat; (B) filtering particles, typically by size; (C) Lysis and DNA extraction; (D) cloning and library construction; (E) sequencing the clones; (F) sequence assembly into contigs and scaffolds