Chapter 13 - Biotechnology Biology 111 - Metz Chapter 13 - Biotechnology What is biotechnology? What is biotechnology used for? When did biotechnology begin? What are the basic techniques used in modern biotechnology? How is biotechnology influencing human medicine? Chapter 13 Chapter 13

What is biotechnology? Alteration of organisms, cells, or biological molecules to achieve specific practical goals Chapter 13

What is biotechnology used for? Production of pharmaceuticals Production of commercial compounds Agricultural improvements Environmental cleanup To better understand the functions and interactions of genes -Advances in medical treatments -Advances in agriculture Diagnosis of genetic disorders Forensics Chapter 13

When did biotechnology begin? Genetic manipulation/alteration of organisms has been occurring for over 10,000 years Chapter 13

Historical vs. modern genetic manipulation Historical – breeding Chapter 13

Domestication of crops began ~10,000B.C. Chapter 13

Genetic manipulation in the Brassica family Europe & Mediterranean Chapter 13

Teosinte – ancestor of corn (Mexico) Cob selection 5000BC – 2cm 3000BC – 4cm 1000AD – 13cm Chapter 13

What are the basic techniques of modern biotechnology? Recombinant DNA technology -Moving small pieces of DNA between organisms -Cloning Genes -Isolating DNA from cells -Restriction enzymes -Polymerase Chain Reaction -Gel electrophoresis -DNA probes -Genetic engineering Viral mediated gene transfer Gene Gun Agrobacterium tumefaciens DNA microarrays Chapter 13

Recombinant DNA technology Combining genes or parts of genes from different organisms Transgenic – organisms containing “foreign” genes Genetically modified organisms = GMOs Chapter 13

Recombinant products rBST and dairy products Chapter 13

DNA recombination occurs naturally Is combining genes from different species inappropriately tampering with God’s creation? DNA recombination occurs naturally 1. Sexual reproduction 2. Bacterial transformation 3. Viral transfer of DNA Chapter 13

Technologies used in cloning genes Isolating DNA from cells Restriction enzymes Gel electrophoresis Polymerase chain reaction Hybridization Chapter 13

Isolating DNA from cells Cell membranes are lysed in detergent Proteins are removed by precipitation DNA is precipitated with alcohol Chapter 13

Restriction enzymes cut DNA molecules Restriction endonucleases (enzymes) cut DNA at specific short palindromic nucleotide sequences Chapter 13

Agarose gel electrophoresis Chapter 13

Gel electrophoresis separates DNA fragments by size Chapter 13

Polymerase chain reaction (PCR) Copies specific DNA sequences A thermal cycler Chapter 13

Polymerase chain reaction (PCR) 25-30 PCR cycles yield ~1 million copies of the DNA sample Can be used on trace quantities of DNA Saliva, hair follicle, trace dried blood Chapter 13

Hybridization – detection of specific DNA sequences (utilizes complementary base pairing) Southern blotting animation Chapter 13

Forensic DNA analysis & hybridization RFLP (Restriction Fragment Length Polymorphism) analysis Began in 1985 Chapter 13

RFLP analysis and hybridization Chapter 13

RFLP Case Study - OJ Simpson Chapter 13

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Hybridization & medicine: Diagnosis RFLP analysis can be used in genetic disease diagnosis (sickle-cell anemia) Chapter 13

Modern forensic DNA analysis Based on the Polymerase Chain Reaction and STRs (Short tandem repeats) Chapter 13

STRs and identity Number of repeats varies (i.e. There are numerous STR “alleles”) Chapter 13

PCR, STRs and identity The greater the number of repeats, the longer the DNA pieces amplified by PCR Chapter 13

What are the basic techniques of modern biotechnology? Genetic engineering - Addition, deletion, or modification of genes in an organism Genetic engineering is not limited to the genome of the organism being manipulated Chapter 13

Genetic engineering & agriculture Chapter 13

Genetic engineering in plants: Gene gun Biology 111 - Metz Genetic engineering in plants: Gene gun Figure: FIGURE 13.7 Title: Inserting genes into plant cells Caption: Genetic engineering techniques have been used to insert a firefly gene that codes for the enzyme luciferase into this tobacco plant. The enzyme breaks down the chemical luciferin, releasing light in the process. This plant has taken up water containing luciferin. Chapter 13 Chapter 13

Genetic engineering in plants: Agrobacterium tumefaciens Biology 111 - Metz Genetic engineering in plants: Agrobacterium tumefaciens Figure: FIGURE 13.E1b Title: Biotechnology may help the American chestnut Caption: Chestnut blight fungus has produced a lesion on this chestnut tree. The lesioned area was treated with infected fungus, and the tree is walling off the infection with a growth of new tissue. Chapter 13 Chapter 13

Plant biotechnology: Insect resistant crop plants Bacillus thuringiensis (BT) Chapter 13

Bacillus thuringiensis BT spores form insecticidal crystal proteins Chapter 13

Plant biotechnology: Herbicide resistant plants Chapter 13

Genetic engineering of animals Genzyme GFP Salmon growth hormone gene engineered for constitutive (always on) expression Chapter 13

How is biotechnology influencing human medicine? Disease diagnosis and DNA arrays Microarray construction link Chapter 13

How is biotechnology influencing human medicine? Correlating genes & disease Chapter 13

Biotechnology & whole genome analysis Whole genome arrays ~$300-500 each Chapter 13

How is biotechnology influencing human medicine? Chapter 13

Somatic Cell Gene Therapy Biology 111 - Metz Somatic Cell Gene Therapy Figure: FIGURE 13.11 Title: Hope through gene therapy Caption: (a) Andrew Gobea (shown with his mother) received gene therapy on stem cells as a newborn. Eventually, he may produce adequate numbers of normal immune cells on his own. (b) Genetic engineering of stem cells may permanently replace the defective ADA gene. 1) Stem cells are harvested from umbilical cord blood. 2) A retrovirus engineered to contain normal human ADA genes is mixed with the stem cells in culture. 3) The retrovirus transmits its DNA, including the functional gene, into the stem cells. 4) The engineered stem cells are injected into the same newborn to take up residence in bone marrow and produce normal immune cells. Chapter 13 Chapter 13

Germline Gene Therapy Chapter 13 Biology 111 - Metz Chapter 13 Figure: FIGURE 13.13 Title: Human cloning technology might allow permanent correction of genetic defects Caption: Researchers might derive human embryos from eggs fertilized in culture dishes, using sperm and eggs from the natural parents, one or both of whom have a genetic disorder. When an embryo containing a defective gene grows into a small cluster of cells, a single cell could be removed from the embryo and the defective gene replaced by means of an appropriate vector. Then the repaired nucleus could be implanted into another egg (taken from the mother) whose nucleus had been removed. The repaired, diploid egg cell could then be implanted in the mother’s uterus for normal development. Chapter 13 Chapter 13

American Journal of Medicine, Nov. 2003, p. 563 Chapter 13 American Journal of Medicine, Nov. 2003, p. 563

Biotechnology is regulated Chapter 13

Biotechnology concerns - allergenicity Chapter 13

Biotechnology concerns Gene “escape” via pollen Chapter 13