DNA Technology • Terminology • USES of DNA technology • DNA fingerprinting • protein production • gene therapy • GMO - G enetically M odified O rganisms • cloning • Stem Cells • Genetic Counseling
Jan 07, 2016
DNA Technology
• Terminology
• USES of DNA technology
• DNA fingerprinting
• protein production
• gene therapy
• GMO - Genetically Modified Organisms
• cloning
• Stem Cells
• Genetic Counseling
Nucleic Acids: DNA & RNA - review• DNA
• deoxyribonucleic acid
• w/in DNA
• genes: specific locations in DNA that codes for proteins or traits
• program the production of proteins
• determines traits for organisms
• RNA
• helps in translating code
DNA & RNA - monomers:
nucleotides
• sugar
• DNA - deoxyribose
• RNA - ribose
• phosphate group
• nitrogenous bases
• DNA --
• adenine (A); thymine (T); cytosine (C); and guanine (G)
• RNA --
• same, except uracil (U) instead of thymine
fig 3.6b
Closer Look at DNA molecule - string of nucleotides:
• backbone of sugar & phosphate
• deoxyribose
• four bases
• A, T, G, C
• double helix
• twisted double stranded molecule
Base Pairing: • AT/GC rule
– A with T
– G with C
• 2 DNA strands are complementary
fig 11.11
•DNA gene sequence •mRNA & tRNA work together to determine • 3-base codons code for specific amino acids
• sequence of amino acids determine specific proteins
How does proteins affect observable traits of organisms?
Example: eye color in fruit flies
• normal gene codes for red eyes
• Mutations code for brown or white
Restriction Enzyme
• cut DNA in specific spots depending on the code in the enzyme
Bacterial Vectors
• Bacteria used to carry pieces of genetic information from other organisms
• plasmids – ring shaped DNA
• Recombinant DNA
• Bacterial plasmid and inserted gene
DNA Technology - Terminology:DNA Technology - Terminology:
Restriction Enzymes:
• cut DNA
• enzymes
• cut at specific base sequence
Forming Recombinant DNA using Restriction Enzymes:
• cut DNA at specific sequences creating fragments
• addition of DNA from other source
• new DNA fragment created
• joined by ligase
Making “customized” bacteria
(1) DNA fingerprinting(1) DNA fingerprinting
• Extract a sample of DNA
• break cell & nuclear membranes
• cut DNA with restriction enzymes
• separate DNA fragments using electrophoresis
•Make DNA visible by staining and attaching to radioactive markers
Uses of DNA technology:Uses of DNA technology:
fig 11.2
• DNA is a negatively charged molecule
• placing it on a special liquid gel and running current through the gel will cause DNA to move from negative pole to positive pole
• the large fragments move the least
•Smaller fragments move the farthest
Gel Electrophoresis:Gel Electrophoresis:
fig 11.2
Reading the gels:Reading the gels:
fig 11.5
(2) Protein production(2) Protein productionUses of DNA technology:Uses of DNA technology:
• use of microbes & cultured cells
• produce
• bacterial clones grown
• protein
fig 11.12
(3) Gene Therapy(3) Gene TherapyUses of DNA technology:Uses of DNA technology:
• patient has defective gene
•
•
• virus
• inserts
fig 11.19
• bone marrow stem cells have potential to develop into different blood / immune cells
(4) Genetically (4) Genetically Modified OrganismsModified Organisms
Uses of DNA technology:Uses of DNA technology:
•
• “increase”
• btCorn (resistant to corn borer)
• golden rice (increase of Vitamin A production)
(4) Cloning(4) CloningUses of DNA technology:Uses of DNA technology:
• clone: genetic replica
• reproductive cloning
•
• therapeutic cloning
•
•
•
fig 11.17
Stem Cell categories
•Totipotent– –
•Pluripotent–Embryonic Stem cells (ES cells)
–Embryonic Germ cells(EG cells)
• Multipotent
–Hematopoietic stem cells (HScs)– umbilical cord blood – bone marrow
• Unipotent–
–
Stem Cell categories
Genetic Counseling:
• Genes for particular disorders are known
• may be markers than can be tested for
• determine probability of
• Huntington’s Disease
• If one parent has a copy of the gene 50% chance for offspring
•If both parents have a copy 75%
• Breast Cancer
• BRAC1 and BRAC2 gene
Genetic Testing // IVF Genetic Screening
• pedigree analysis or direct genetic testing available for Cystic Fibrosis
• parents with a family history of Cystic Fibrosis can screen embryos for the disorder PRIOR to in vitro fertilization
• • fertilization occurs
• single cell removed
• embryos
• first child as the result of this screening born in 1990