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Genomes & Gene Organization. 7.6. What is a genome?. “an organism’s complete set of DNA, including all of its genes” (http://ghr.nlm.nih.gov/handbook/hgp/genome) the Human Genome Project sequenced the 3 billion base pairs that make up the human genome. Comparative Genomics.
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What is a genome? • “an organism’s complete set of DNA, including all of its genes” (http://ghr.nlm.nih.gov/handbook/hgp/genome) • the Human Genome Project sequenced the 3 billion base pairs that make up the human genome
Genome Components • eukaryotic genomes are composed of coding and non-coding regions • human genome: • < 2% codes for proteins • 24% is introns • almost 75% is between the genes (some is functional (promoters, etc.) but more than 50% of total is non-functional)
Eukaryotic Non-coding DNA • variable number tandem repeats (VNTRs) or microsatellites • LINEs (long interspersed nuclear elements); about 6500 bp long • SINEs (short interspersed nuclear elements); about 500 bp long
More non-coding DNA… • transposons are small sequences of DNA that can move • pseudogenes are similar to existing genes (possibly mutated versions of older genes?); e.g. dolphins & sense of smell
Is more better? • mammalian genome 300 times larger than yeast genome but there are almost the same number of genes in both • complexity of organisms is more likely related to organization & regulation rather than the size of the genome