DNA TECHNOLOGY AND THE
HUMAN GENOME
DNA TECHNOLOGY AND THE HUMAN
GENOME
• MOST DNA TECHNOLOGY IS NATURALLY
OCCURING PHENOMENA THAT WE
MANIPULATE TO SERVE OUR CURIOUSITY AND
INTEREST
– BACTERIAL TRANSFORMATION
– BACTERIAL TRANSDUCTION
– BACTERIAL CONJUGATION
– RESTRICTION ENZYMES
DNA TECHNOLOGY AND THE HUMAN
GENOME
• BACTERIAL
– TRANSFORMATION 
– TRANSDUCTION 
– CONJUGATION 
DNA TECHNOLOGY AND THE HUMAN
GENOME
• BACTERIAL CONJUGATION
– REQUIRES THE
PRESENCE OF AN
“F” FACTOR
– “F” FACTOR 
“F” = FERTILITY
• MAY EXIST
INTEGRATED IN
BACTERIAL DNA, OR
AS A SEPARATE
STRUCTURE CALLED A
PLASMID
– PLASMID  A SMALL, CIRCULAR DNA MOLECULE
SEPARATE FROM THE MUCH LARGER BACTERIAL
CHROMOSOME
DNA TECHNOLOGY AND THE HUMAN
GENOME
• VECTOR  A PLASMID CARRYING EXTRA
GENES OTHER THAN THOSE NEEDED FOR
REPLICATION AND CONJUGATION
• “F” PLASMID NOT THE ONLY PLASMID
• “R” PLASMID = RESISTANCE TO ANTI-BIOTICS
• PRESENCE OF “R” PLASMID MAY LEAD TO “SUPERBACTERIA”
DNA TECHNOLOGY AND THE HUMAN
GENOME
• HOW ARE PLASMIDS USED?
– A PLASMID IS ISOLATED FROM A BACTERIUM
– DNA CARRYING A GENE OF INTEREST IS OBTAINED
FROM ANOTHER CELL
– A PIECE OF DNA CONTAINING THE GENE INSERTED
INTO THE PLASMID
– A BACTERIAL CELL TAKES UP THE PLASMID BY
TRANSFORMATION
– THIS GENETICALLY ENGINEERED, RECOMBINANT
BACTERIUM IS THEN CLONED, OR ALLOWED TO
MITOTICALLY DIVIDE, TO GENERATE MANY COPIES OF
THE GENE
DNA TECHNOLOGY AND THE HUMAN
GENOME
• HOW DO WE “CUT AND
PASTE” DNA
– RESTRICTION ENZYMES 
NATURALLY OCCURING
BACTERIAL ENZYMES
THAT ARE USED AS
CUTTING TOOLS FOR
MAKING RECOMBINANT
DNA
DNA TECHNOLOGY AND THE HUMAN
GENOME
• RESTRICTION ENZYMES
– BACTERIA CONTAIN THEM AS PROTECTION
AGAINST FOREIGN DNA (LIKE??)
– PRODUCE DNA FRAGMENTS, OFTEN WITH “STICKY
ENDS”
– REQUIRE DNA LIGASE TO SEAL/PASTE FRAGMENTS
TOGETHER
– CAN PRODUCE RECOMBINATION DNA
• RECOMBINANT DNA  A DNA MOLECULE CARRYING A
NEW COMBINATION OF GENES
DNA TECHNOLOGY AND THE HUMAN
GENOME
• RESTRICTION
ENZYMES AND
RECOMBINATN
PLASMIDS CAN BE
USED TO CLONE
GENES
DNA TECHNOLOGY AND THE HUMAN
GENOME
DNA TECHNOLOGY AND THE HUMAN
GENOME
• TO SAVE TIME WE
– CREATE GENOMIC LIBRARIES
• ENTIRE COLLECTIONS OF CLONED DNA FRAGMENTS (THIS
ALLOWS SCIENTISTS TO SKIP THE STEP OF CONSTANTLY
ISOLATING GENES FROM HUGE DNA MOLECULES)
– UTILIZE cDNA
• cDNA  COMPLEMENTARY DNA; DNA THAT RESULTS FROM
THE REVERSE TRANSCRIPTION OF mRNA BY USING
_____________________ ??
• WHY IS IT MORE HELPFUL/EASIER TO USE mRNA TO
DISCOVER THE DNA SEQUENCE??
DNA TECHNOLOGY AND THE HUMAN
GENOME
• GEL ELECTROPHORESIS
– A METHOD FOR PHYSICALLY
SORTING MACROMOLECULES –
PROTEINS OR NUCLEIC ACIDS –
PRIMARILY ON THE BASIS OF
THEIR ELECTRICAL CHARGE AND SIZE
DNA TECHNOLOGY AND THE HUMAN
GENOME
• GEL ELECTROPHORESIS
– RESTRICTION FRAGMENT ANALYSIS
• RESTRICTION FRAGMENTS  PIECES OF DNA THAT
RESULT FROM RESTRICTION ENZYME ACTION
– VARIOUS LENGTHS BASED ON DNA SEQUENCE AND
RESTRICTION ENZYMES USED
• DIFFERENT PEOPLE WILL HAVE DIFFERENT RESTRICTION
FRAGMENTS
• RELATIVES SHOULD HAVE MORE FRAGMENTS IN
COMMON, SINCE THEY HAVE SIMILAR DNA
DNA TECHNOLOGY AND THE HUMAN
GENOME
DNA TECHNOLOGY AND THE HUMAN
GENOME
• GEL ELECTROPHORESIS
– RESTRICTION FRAGMENT
ANALYSIS
• CAN BE USED TO DETECT
HARMFUL ALLELES; DIFFERENT
ALLELES HAVE DIFFERENT DNA
SEQUENCES, THEREFORE,
DIFFERENT RESTRICTION
FRAGMENTS
• CAN BE USED IN THE COURT
OF LAW TO IDENTIFY
SUSPECTS (DNA FINGERPRINTS)
DNA TECHNOLOGY AND THE HUMAN
GENOME
• IF THERE IS ONLY A
SMALL SPECK OF BLOOD
AT A CRIME SCENE, HOW
CAN THEY DO SO MANY
GENETIC TESTS?
– PCR (POLYMERASE
CHAIN REACTION)
• A TECHNIQUE BY WHICH
ANY SEGMENT OF DNA
CAN BE CLONED/AMPLIFIED
WITHOUT USING LIVING CELLS
DNA TECHNOLOGY AND THE HUMAN
GENOME
• GENE THERAPY
– ALTERATION OF AN
AFFLICTED
INDIVIDUAL’S GENES
– MANY TECHNICAL
AND ETHICAL
QUESTIONS SURROUND
THIS CONCEPT
• ANYONE SEE “I AM
LEGEND”??
– EUGENICS 
DNA TECHNOLOGY AND THE HUMAN
GENOME
• DNA IS PRESENT IN
ALL LIFE; THE STUDY
OF DNA HAS LED TO
DISCOVERIES THAT
SHOW SUCH SIMILARITY
IN DNA BETWEEN SUCH
DIFFERENT TYPES OF
ORGANISMS, THAT IT
LEADS US TO THE
QUESTION…WHAT DOES
THIS SIMILARITY SUGGEST
ABOUT ALL LIVING THINGS?
THIS WILL BE THE FOCUS OF
OUR DISCUSSIONS AFTER
FEBRUARY BREAK!! ENJOY
YOURSELVES!!