* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Genomics - West High School
RNA silencing wikipedia , lookup
Non-coding RNA wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
Gene expression profiling wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Gene expression wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Promoter (genetics) wikipedia , lookup
Molecular cloning wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Genomic library wikipedia , lookup
Point mutation wikipedia , lookup
Community fingerprinting wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Genome evolution wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Endogenous retrovirus wikipedia , lookup
Non-coding DNA wikipedia , lookup
Genomics The field of biology based on studying the entire DNA sequence of an organism - its “genome”. Genomics tools don’t replace classical genetics tools, they are complementary. 1 Classical Genetics (forward genetics): 1. Mutant studies A. Find mutants and reproduce them •Natural mutations •Create mutations by using mutagens (selective pressure for mutants to survive) example: antibiotic resistant bacteria B. Study genes one at a time 2 What makes Genomics a new way to study biology? Genomics: Using tools to study all the genes in an organism (the entire genome) simultaneously once its sequence is known. (~ 190 organisms as of March 2007) How do we do this? 3 Genomics methods Be Efficient: 1. Work with Model Organisms Share resources and information E. coli (Bacterium) Arabidopsis (Plant) ZebraFish Dictyostelium (Slime mold) Xenopus (African clawed frog) Drosophila (Fruit Fly) Mouse S. cerevisiae (Yeast) C.elegans (Worm) 4 Genomics methods cont’d 2. Use Reverse Genetics: A. Insert tagged DNA sequences (T-DNA) at random sites throughout the genome. If the insertion disrupts a gene, then it might cause an observable phenotype. B. Grow the organism. C. Look for mutant phenotypes. .…Since the insertion has a specific sequence (a tag), you can figure out where the insertion went in the genome =>then you figure that gene is related to that phenotype. Voilà! 5 Genomics Methods, Cont’d 3. Use High through-put methods that produce huge datasets ==> One method is a Microarray 6 Microarrays (slang: DNA chips) Ordered array of different known sequences of DNA (~20-70 bp) on a solid surface (glass) Can have thousands of “spots”. This slide has 18 Gene 1 Gene 18 Gene 2 7 “DNA Chip” Slang for DNA Microarray =>Technology using a biological molecule: DNA A G T C •many different DNA sequences stuck to a flat surface •tens of thousands of spots •can probe tens of thousands of DNA sequences all at once 8 How do Microarrays work? In general: 1. Cells express certain genes under certain conditions and make RNA 2. RNA is isolated and tagged with a dye 3. Tagged RNA is placed on a microarray containing representative sequences of thousands of genes at known addresses on the chip 4. Microarray is scanned to locate where dye is => this is where RNA has attached => voila! these genes were expressed 9 “Alien “ oligos be spiked Labeled Targetcan DNA made onto the array spots as well as from RNA present in cells (a into the treatment+reference “snapshot” of gene mix in known concentrations. expression) Hybridized target to Probe DNA Probe DNA stuck to glass 10 Temple Smith, Boston U