Biotechnology DNA Cloning Finding Needles in Haystacks DNA Sequencing Genetic Engineering Gene Therapy
What is DNA Cloning? Set of methods that uses live cells to make many identical copies of a DNA fragment Restriction enzyme Cuts DNA at specific nucleotide sequences Leave single-stranded tails/ sticky ends
Recombinant DNA A DNA molecule that contains genetic material from more than one organism
Cloning vector A DNA molecule that accepts foreign DNA and carry it into a host cell/ bacterial plasmids
DNA cloning mass produces specific DNA fragments Inserting gene for pest resistance Altering bacteria for cleaning up toxic waste Stone washed jeans Protein to dissolve blood clots
cdna Complementary strand of DNA synthesized from an RNA template using an enzyme called reverse transcriptase What is cdna Cloning?
DNA libraries are sets of cells that host cloned DNA fragments Ø A genomic library collectively contains all DNA in a genome Ø A cdna library contains only those genes being expressed when mrna was harvested Probe Ø Short fragment of DNA labeled with a tracer Ø Designed to hybridize with a nucleotide sequence of interest
Polymerase chain reaction (PCR) Technique used to mass-produce copies of sections of DNA without having to clone in living cell Thermocycler DNA Nucleotides Taq Polymerase Primers Buffers Denaturation Annealing Elongation
DNA Sequencing Figure 15-6 p242
Electrophoresis
Genomics Study of whole genomes
Human Genome Project Human genome consists of about three billion nucleotide bases Only about 21,000 genes Only about 1.5% of DNA contains genes that code for proteins
Costs are Decreasing Dramatically Genome Length Time to complete Cost by Sanger Time to complete Cost by Illumina Yeast 0.012 Gb 3 years $10 mil < 2 week < $20 Arabidopsis 0.125 Gb 4 years $70 mil < 2 week < $200 Human 3 Gb 5+ years ~$1 billion < 2 week ~$4000 Since 2001 costs have decreased from >$500,000 per Gb (Sanger) to <$1500 per Gb (next gen)
DNA Profiling Analysis of DNA samples to see if they came from the same individual
Genetic Engineering Ø Process by which an individual s genome is deliberately modified Ø Produces a genetically modified organism (GMO) Ø A gene may be altered and reinserted into an individual of the same species Ø A gene from one species may be transferred to another to produce an organism that is transgenic Ø Most common GMOs are bacteria and yeast
GM bacteria Engineered Microorganisms Ø Produce medically important proteins such as insulin Ø Produce enzymes used in food manufacturing, such as chymotrypsin Ø Produce enzymes used to improve taste of beer and fruit juice and slow bread from staling
GM Plants Disease resistance Improved yield Improved salt, frost,. tolerance Improved nutritional value* Resistance to pesticides *
The case of BT corn Enhanced through biotechnology to enable it to protect itself against the corn borer, which is one of the most destructive insects to damage or reduce corn production and one of the most economically significant crop pests in the world Monarch butterflies
GM Animals Ø Mice: used for medical research Ø Goats: genetically engineered to have proteins that treat cystic fibrosis, heart attacks, nerve gas exposure, etc. Ø Rabbits: genetically engineered to make interleukin-2 Ø Pigs: modified for heart-healthy fat and lower phosphate feces Ø Trout and salmon: bigger versions Ø Farm animals: produce more meat or milk
www.gmoanswers.com
Gene Therapy Experimental technique that uses genes to treat or prevent diseases Ø Replacing a mutated gene that causes a disease with a healthy copy of the gene Ø Inactivating a mutated gene that is functioning improperly Ø Introducing a new gene into the body to help fight a disease
Gene therapy is currently only being tested for the treatment of diseases that have no other cures In 2000: gene therapy used to treat 10 children with severe combined immunodeficiency disease (SCID) 9 showed improvement but developed leukemia The technique remains risky and is still under study to make sure that it will be safe and effective