cloning

Examples of cloning in the following topics:

• Reproductive Cloning

  • Reproductive cloning, possible through artificially-induced asexual reproduction, is a method used to make a clone of an entire organism.
  • Reproductive cloning is a method used to make a clone or an identical copy of an entire multicellular organism.
  • This idea forms the basis for reproductive cloning.
  • It can be used for either therapeutic cloning or reproductive cloning.
  • Dolly the sheep was the first mammal to be cloned.

• 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.

• Modern Applications of DNA

  • Reproductive cloning is a method used to make a clone or an identical copy of an entire multicellular organism.
  • In cloning both the original organism and the clone have identical DNA.
  • Cloning became an issue in scientific ethics when a sheep became the first mammal cloned from an adult cell in 1996.
  • There have been attempts at producing cloned human embryos as sources of embryonic stem cells, sometimes referred to as 'cloning for therapeutic purposes'.
  • Dolly the sheep was the first large mammal to be cloned.

• 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 .

• Molecular and Cellular Cloning

  • Molecular cloning reproduces the desired regions or fragments of a genome, enabling the manipulation and study of genes.
  • In general, the word "cloning" means the creation of a perfect replica; however, in biology, the re-creation of a whole organism is referred to as "reproductive cloning."
  • Long before attempts were made to clone an entire organism, researchers learned how to reproduce desired regions or fragments of the genome, a process that is referred to as molecular cloning.
  • In cloning, the plasmid molecules can be used to provide a "folder" in which to insert a desired DNA fragment.
  • Unicellular organisms, such as bacteria and yeast, naturally produce clones of themselves when they replicate asexually by binary fission; this is known as cellular cloning.

• 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.

• Production of Vaccines, Antibiotics, and Hormones

  • Modern techniques use the genes of microorganisms cloned into vectors to mass produce the desired antigen.
  • Genes cloned from the influenza virus have been used to combat the constantly-changing strains of this virus.
  • The HGH gene was cloned from a cDNA library and inserted into E. coli cells by cloning it into a bacterial vector.