Recombinant DNA Technology

• Escherichia coli (E.coli) is the source of the first identified restriction endonuclease, named EcoRI.

• Restriction enzymes derive their names from the bacterial species they come from.

• Restriction enzymes work by recognizing and binding to specific palindromic sequences in DNA, cutting between G and A residues.

• Sticky ends are produced by some restriction enzymes, which leave single-stranded overhangs and help in DNA cloning by allowing fragments to join through complementary base pairing.

• Blunt ends result when a restriction enzyme cuts both strands at the same position, leaving no overhangs and making ligation less efficient and more complex.

• Host cells protect their own DNA from restriction endonucleases through methylation.

• Vectors are DNA molecules used to carry and propagate foreign DNA in a host cell, and have specific sites for insertion of target DNA, origins of replication, selectable markers, and multiple cloning sites.

• Plasmids are circular extrachromosomal DNA molecules used as vectors, which can be found in bacteria, eukaryotes, and archaea, and are small, easy to detect due to antibiotic resistance genes, and have a limited insert size.

• Bacteriophages are used as vectors due to their large insert size and ease of screening through plaque formation.

• Cosmids are hybrid vectors that combine plasmid and bacteriophage features, allowing for the cloning of larger DNA fragments.

• Bacterial Artificial Chromosomes (BACs) and Yeast Artificial Chromosomes (YACs) are large DNA constructs used for cloning, with BACs having a bacterial origin and a maximum insert size of 300 kb, and YACs having a yeast origin and a maximum insert size of 2000 kb.

• Recombinant DNA is introduced into a host cell for replication and expression, with bacteria, yeast, and mammalian cells being used depending on the desired product.

• Escherichia coli (E.coli) is the source of the first identified restriction endonuclease, named EcoRI.

• Restriction enzymes derive their names from the bacterial species they come from.

• Restriction enzymes work by recognizing and binding to specific palindromic sequences in DNA, cutting between G and A residues.

• Sticky ends are produced by some restriction enzymes, which leave single-stranded overhangs and help in DNA cloning by allowing fragments to join through complementary base pairing.

• Blunt ends result when a restriction enzyme cuts both strands at the same position, leaving no overhangs and making ligation less efficient and more complex.

• Host cells protect their own DNA from restriction endonucleases through methylation.

• Vectors are DNA molecules used to carry and propagate foreign DNA in a host cell, and have specific sites for insertion of target DNA, origins of replication, selectable markers, and multiple cloning sites.

• Plasmids are circular extrachromosomal DNA molecules used as vectors, which can be found in bacteria, eukaryotes, and archaea, and are small, easy to detect due to antibiotic resistance genes, and have a limited insert size.

• Bacteriophages are used as vectors due to their large insert size and ease of screening through plaque formation.

• Cosmids are hybrid vectors that combine plasmid and bacteriophage features, allowing for the cloning of larger DNA fragments.

• Bacterial Artificial Chromosomes (BACs) and Yeast Artificial Chromosomes (YACs) are large DNA constructs used for cloning, with BACs having a bacterial origin and a maximum insert size of 300 kb, and YACs having a yeast origin and a maximum insert size of 2000 kb.

• Recombinant DNA is introduced into a host cell for replication and expression, with bacteria, yeast, and mammalian cells being used depending on the desired product.

Learn about the fundamentals of recombinant DNA technology, including gene cloning, genetic engineering, and molecular cloning. Understand how DNA can be produced through artificial means and how recombinant DNA is constructed from different sources using restriction enzymes, DNA ligase, and vectors.