1 / 24

Genomes

Genomes. Chapter 17. Outline. Genome Maps Genome Sequencing Human Genome Project Genome Geography Variation in the Human Genome Comparative Genomics Functional Genomics Proteomics. Genome Maps.

benita
Download Presentation

Genomes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Genomes Chapter 17

  2. Outline • Genome Maps • Genome Sequencing • Human Genome Project • Genome Geography • Variation in the Human Genome • Comparative Genomics • Functional Genomics • Proteomics

  3. Genome Maps • Genetic maps show the relative location of genes on a chromosome as determined by recombination frequencies. • measured in centimorgans (cM) • one cM = 0.01% recombination

  4. Genome Maps • Physical maps are diagrams showing the relative positions of landmarks within specific DNA sequences. • measured in base-pairs (bp) • 1,000 base pairs equal 1 kilobase (kb) • use restriction enzymes to cut sequences • use sequenced-tagged sites (STSs) to construct large genome maps

  5. Physical Maps with Restriction Enzymes

  6. Physical Maps with Sequence-Tagged Sites

  7. Genome Sequencing • Sequencing • sequencing of entire genomes now practical due to technological advances • sequencers provide accurate sequences for DNA segments up to 500 bp long • five to ten genome copies sequenced to reduce errors

  8. Sequencing DNA

  9. Genome Sequencing • Artificial chromosomes • vector used in cloning larger pieces of DNA • yeast artificial chromosomes (YAC) • bacterial artificial chromosomes (BAC) • Sequencing by whole genomes • clone-by-clone sequencing - cloning larger inserts in BAC requires construction of a physical map, then placing site of BAC clones for later sequencing

  10. Genome Sequencing • shotgun sequencing - sequence all cloned fragments and use a computer to put together overlaps • requires abundant computing power • does not tie the sequence to any other information about the genome • assembler programs assemble a consensus sequence

  11. Method Comparison

  12. Human Genome Project • Human genome contains 3.2 gigabases • announced on June 26, 2000, that the entire human genome had been sequenced • International Human Genome Sequencing Consortium • draft sequence contains gaps still being filled in

  13. Genome Size and Complexity

  14. Genome Geography • Must now be determined which regions of the genome contain which genes, and what those genes do • Bioinformatics uses computer programs to search for genes, compare genomes, and assemble genomes. • open reading frame (ORF) • expressed sequence tag (EST)

  15. Gene Organization • Four classes of protein-encoding genes are found in eukaryotes. • single-copy genes • segmental duplications • multigene families • tandem clusters

  16. Eukaryotic Noncoding DNA • Six major sorts of noncoding human DNA • noncoding DNA within genes • structural DNA • simple sequence repeats • segmental duplications • pseudogenes • transposable elements • long-interspersed elements (LINEs) • Short-interspersed elements (SINEs)

  17. Variation in the Human Genome • Single nucleotide polymorphisms (SNPs) in the human genome are being used to look for associations between genes. • expect genetic recombination randomizes all but most tightly linked genes • linkage disequilibrium - tendency for genes to not be randomized • can be used to map genes

  18. Comparative Genomics • Comparisons of whole genome maps reveal a large degree of commonality among organisms. • Synteny refers to conserved arrangements of DNA segments in related genomes.

  19. Functional Genomics • Functional genomics is the study of the function of genes and their products. • DNA Microarrays • DNA fragments are deposited on a microscope slide producing DNA microarrays. • SNPs can serve as markers. • screen large numbers of genes extremely quickly

  20. Proteomics • Cataloging and analyzing every protein in the human body • Gene transcripts may not be translated into a protein at any particular moment. • Must study all the RNA present in a tissue at a specific time, transcriptome, as an intermediate step. • Proteomics utilizes new methods to quickly identify and characterize large numbers of proteins.

  21. Using Genomic Information • Genomics revolution has yielded millions of new genes to be investigated. • improvement of medical diagnostics • improvement in agriculture • biological weapons • Potential problems • gene patents • privacy concerns

  22. Summary • Genome Maps • Genome Sequencing • Human Genome Project • Genome Geography • Variation in the Human Genome • Comparative Genomics • Functional Genomics • Proteomics

More Related