This chapter explain how linkage mapping, physical mapping, and DNA sequencing each contributed to the Human Genome Project, define the fields of proteomics and genomics, describe the surprising findings of the Human Genome Project with respect to the size of the human genome, distinguish between transposons and retrotransposons. | Genomes and Their Evolution What you need to know: The major goals of the Human Genome Project How prokaryotic genomes compare to eukaryotic genomes. The activity and role of transposable elements and retrotransposons. How evo-devo relates to our understanding of the evolution of genomes. The role of homeotic genes and homeoboxes. Bioinformatics Use of computers, software, and math models to process and integrate data from sequencing projects Human Genome Project Purpose: to sequence the entire human genome Completed in 2003 Genomes sequenced thus far*: 58,000 prokaryotes, 2700 eukaryotes, 5300 viruses * Data as of 1/27/16 Human DNA 3 billion base pairs ~20,000 genes Only codes for proteins (or RNA) Mostly Repetitive DNA: sequences present in multiple copies Transposable Elements Make up 75% of repetitive DNA Stretches of DNA that can be moved from one location to another in genome Discovered by Barbara McClintock – corn breeding experiments 2 Types: Transposons Retrotransposons Transposons Moves within genome via DNA intermediate “cut & paste” or “copy & paste” mechanisms Requires enzyme transposase Retrotransposons Move by means of RNA intermediate Leaves copy at original site Involves enzyme reverse transcriptase Genome Evolution Insertion effects of transposons: Can interrupt or alter gene function Multiple copies of genes Duplication genes with related functions Genes diverge by accumulating mutations Some become nonfunctional pseudogenes Eventually, new genes with new functions can occur Multigene Families Collections of 2 or more identical or very similar genes Eg. hemoglobin: -globin and -globin gene families Transposable elements contribute to evolution Promote recombination, disrupt genes or control elements, & carry genes to new locations May be harmful or lethal, but can also have small beneficial effects Provides raw material for natural selection Illustrative Example: Antifreeze Gene in Fish Antifreeze proteins (AFP): produced by vertebrates, | Genomes and Their Evolution What you need to know: The major goals of the Human Genome Project How prokaryotic genomes compare to eukaryotic genomes. The activity and role of transposable elements and retrotransposons. How evo-devo relates to our understanding of the evolution of genomes. The role of homeotic genes and homeoboxes. Bioinformatics Use of computers, software, and math models to process and integrate data from sequencing projects Human Genome Project Purpose: to sequence the entire human genome Completed in 2003 Genomes sequenced thus far*: 58,000 prokaryotes, 2700 eukaryotes, 5300 viruses * Data as of 1/27/16 Human DNA 3 billion base pairs ~20,000 genes Only codes for proteins (or RNA) Mostly Repetitive DNA: sequences present in multiple copies Transposable Elements Make up 75% of repetitive DNA Stretches of DNA that can be moved from one location to another in genome Discovered by Barbara McClintock – corn breeding experiments 2 Types: Transposons Retrotransposons
