* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Agrobacterium
DNA sequencing wikipedia , lookup
Comparative genomic hybridization wikipedia , lookup
Mitochondrial DNA wikipedia , lookup
DNA profiling wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Human genome wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Metagenomics wikipedia , lookup
Point mutation wikipedia , lookup
Cancer epigenetics wikipedia , lookup
DNA polymerase wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
United Kingdom National DNA Database wikipedia , lookup
SNP genotyping wikipedia , lookup
Genealogical DNA test wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
Genomic library wikipedia , lookup
Genetically modified crops wikipedia , lookup
DNA vaccination wikipedia , lookup
Genome (book) wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
Genome editing wikipedia , lookup
Microsatellite wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Epigenomics wikipedia , lookup
Primary transcript wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Bisulfite sequencing wikipedia , lookup
DNA supercoil wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Non-coding DNA wikipedia , lookup
Molecular cloning wikipedia , lookup
Designer baby wikipedia , lookup
Helitron (biology) wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Genetic engineering wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Microevolution wikipedia , lookup
INTRO TO MOLECULAR GENETICS •Restriction enzymes •Mapping •Cloning •PCR •Sequencing •Genetic engineering A restriction enzyme cuts DNA at a specific sequence (Bacteria are safe because their DNA is methylated (with a CH3 group) at these sites.) RFLPs were an early form of genetic marker http://www.mun.ca/biology/scarr/RFLP_test_for_recessive_trait.html Click here to see a map of Chromosome 6 in humans: http://www.ncbi.nlm.nih.gov/mapview/maps.cgi?taxid=9606&chr=6 Various kinds of information were used to make these maps. Chromosome 6 contains about 1500 genes. You can see more of them if you zoom in on the right-most map. Molecular Cloning -make many copies of certain strands of DNA If use messanger RNA, as here, will clone DNA that is expressed in a certain tissue. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. If clone into “expression vector” can make gene product. Can also clone “genomic DNA”, which will include non-coding regions. Polymerase Chain Reaction (PCR) Efficient way to make many copies of a piece of DNA. Has replaced cloning for some applications. You will need: •Double stranded DNA (the template) •Primers (two ~ 20 bp single-stranded oligonucleotides that are complementary to the template, spanning the region of interest.) •DNA polymerase, preferably from a hot-spring bacterium •dNTPs (dioxynucleotide triphosphates A, C, G, and T) •Buffer to run the reaction in PCR repeats 3 steps: 1. Denaturation 2. Primer annealing QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 3. Extension At each repetition, the number of copies of DNA doubles. It’s fun and easy! DNA sequencing Normal (deoxy) dNTP (extends strand) Di-deoxy nucleotide ddNTP (terminates extension) Requires: A mix of dNTPs and ddNTPs Polymerase A labeled primer Generates: QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A mix of fragments. The length of each fragment indicates which ddNTP was added, and therefore the base at that position. We use automated sequencing here at Colby. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. What do we do with this new information? Genetic testing Improved understanding of phenotype & treatments Information on relatedness of populations and species Genetic engineering? QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. genes enter host cell. both viral and human sequences . stranded DNA version of introduced genes. Retroviruses can carry the desired DNA into human cells. These viruses carry reverse transcriptase, which uses RNA as a template to make DNA. Sometimes, this fragment will be incorporated into the host (human) genome. Problems: Viruses are scary and germy! Immune system response can be serious. The fragment could happen to land in the middle of a functional gene. More feasible: implant stem cells that have undergone genetic engineering. Genetic engineering is widespread in agriculture. Agrobacterium infects many plants. This bacterium contains a plasmid, an extra-chromosomal piece of DNA. A section of the plasmid is incorporated into the chromosomes of the cells (virus-like), causing them to grow and divide rapidly. Humans can replace these “tumor” genes with genes of our choice. A descriptive animation of cell culture from Agrobacterium transformation: http://www.agriculture.purdue.edu/agbiotech/images/leafdisk1.html A descriptive animation of the gene gun: http://www.agriculture.purdue.edu/agbiotech/images/Genegun1.html Examples of genetically engineered crops: (the FDA has completed consultations on these crops* ) Soybean -- herbicide resistance Corn -- resistance to herbivory by insects; herbicide resistance Sugar beet -- herbicide resistance (the final product contains no DNA or protein) Alfalfa -- herbicide resistance Wheat -- herbicide resistance Rice -- herbicide resistance Canteloupe -- delayed ripening due to reduced ethylene Tomato -- resistance to herbivory by insects; delayed ripening Potato -- resistance to virus and beetles Squash -- resistance to viruses Papaya -- resistance to viruses *http://vm.cfsan.fda.gov/%7Elrd/biocon.html Interesting Purdue website: http://www.agriculture.purdue.edu/agbiotech/onthetable.html