Transcript 042110_recombinant_DNA

Recombinant DNA Technology
• A set of methods used to locate,
analyze, alter, study, and recombine
DNA sequences
• Recombinant DNA is DNA in which
nucleotide sequences from two
different sources (even different
species) are combined in the laboratory
to produce a new combination of genes
Recombinant DNA Technology
• It is used to:
– Probe the structure and function of genes
• If I delete this gene, what happens to the
mouse?
– Address questions in many areas of
biology
• How are Bos taurus and Bos indicus related?
– Create commercial products
• How can I get insulin production from bacteria?
– Diagnose and treat diseases
• Does this child have cystic fibrosis?
Recombinant DNA Technology
• Using Mendelian and other genetic analyses
we have talked about, everything we have
deduced about genes and DNA sequence
has been indirect
• With recombinant DNA technology we can
isolate genes and DNA sequence, study them
directly and store it in a convenient manner
that facilitates future applications
• Cloning the DNA sequence accomplishes all
of these
Review of steps involved
in cloning
• http://highered.mcgrawhill.com/sites/0072556781/student_view0/
chapter14/animation_quiz_1.html
Recombinant DNA Technology
• Restriction enzymes were the key
breakthrough in recombinant DNA
technology and cloning
• Restriction enzymes are used to cleave DNA
at specific sequences
– Cuts DNA at specific sequences into different
sized molecules
– Cuts a single phosphodiester bond on each
strand
Recombinant DNA Technology
• Recognition sequence
– Usually four to six bases
– Palindromes – read the same on both
strands
– Cut DNA reciprocally at specific
recognition sites
Recombinant DNA Technology
• Most restriction enzymes make offset
cuts
– Restriction sites are not opposite each
other
• Results in staggered cuts (sticky ends)
• Ability for hydrogen bonding to a
complementary sequence