Chapter 11 Gene Technology (Biotechnology) Section 1 – Genetic Engineering Section 2 – Human Applications of Genetic Engineering Section 3 – Genetic Engineering in Agriculture

Example – First Genetically Altered Organism Genetic Engineering The process of manipulating genes for practical purposes Involves recombinant DNA DNA made from two or more organisms Example – First Genetically Altered Organism Bacteria produced frog rRNA

Steps of Genetic Engineering Step 1 – Cutting DNA Genes of interest cut by restriction enzymes Restriction Enzymes: Bacterial enzymes that recognize and bind to specific nucleotides Vector An agent used to carry the gene of interest to another cell Plasmids Circular DNA that replicate independently

Steps of Genetic Engineering Step 2 – Making Recombinant DNA Genes of Interest + Vector = Recombinant DNA Transgenic organism The organism produced through genetic engineering DNA Ligase: Bonds (glues) the DNA fragments together Host cells take up the recombinant DNA to pass on the genetically modified DNA

Steps of Genetic Engineering Step 3 – Cloning Gene Cloning: As host cell reproduces – exact copies of the genes of interest are replicated Gene of interest and plasmid are both replicated

Steps of Genetic Engineering Step 4 – Screening The cells that picked up the genes of interest are separated from the cells that did not Only the modified genes are transcribed & translated

Each end are known as sticky ends Recombinant DNA Each end are known as sticky ends In order to bond to the plasmid – they must have complementary base pairing

Cloning Genes - Confirmed Step 1 – Southern Blot DNA cut by restriction enzymes and isolated Step 2 – Gel Electrophoresis Electric field that separates molecules by size DNA is separated into single strands by gel DNA is negatively charged – migrates to positive pole Small bands move the fastest

Cloning Genes - Confirmed Step 3 – Probes Radioactive or fluorescent tags that are complementary to the genes of interest Step 4 – Visible Bands The strands will bind with the probes and create visible bands within the solution

http://video.mit.edu/watch/genetic-engineering-10959/

Human Genome Project A project that links over 20 genetic labs in six different countries The purpose: Identify all 3.2 billion base pairs of the human genome Human DNA: 6 feet long 30,000 to 40,000 genes Expected Number: 120,000 Which is actual the number of mRNA molecules

Genetically Engineered Drugs

Genetically Engineered Drugs Bacteria is the source for many GEDs These drugs are universal for all body types and that’s why they work

Genetically Engineered Vaccine Harmless version of human pathogen The human body creates antibodies at the first response so in future infections it can have immunity

Improving Crops Glyphosate Biodegradable weed killer resistant Crops were modified so they flourished Rice Modification DNA modified to contain iron and beta carotene Fights iron deficiency and improves vision

Risks of GM Crops Potential Problems Glyphosate resistant crops could lead to glyphosate resistant weeds Humans could be allergic to the gene insert to modify the crops Environment Effect Pest can become resistant GM crops could become the new wild plant

Technology in Animal Farming Growth Hormone in Cows Increases milk production Introduced through bacteria in their diet Now naturally in pigs Transgenic Organisms Human proteins introduced to farm animal DNA to produce human proteins in milk

Cloning Using undifferentiated cells from an adult animal to produce an offspring through differentiation

Genomic imprinting Problems with Cloning Chemical locking “on” and “off” of a gene without DNA alteration Use of methyl group – CH3 Cloning Failure Egg divides in minutes which is too fast to properly form specialized cells

A pattern of dark bands on X-ray film DNA Fingerprinting A pattern of dark bands on X-ray film Needs Polymerase Chain Reaction Used to amplify and make multiple (millions of copies) of the same DNA sequence This must be done before DNA fingerprinting process begins if sample is too small!

DNA Fingerprinting Process: DNA cut by restriction enzymes between CCGG In gel – small fragments move to positive side (DNA is negatively charged) When bands line up – you can compare DNA to see if they are matched Example – Blood samples at crime scenes