| | The Human Genome: Important Insights | In 1990, geneticists around the world tackled one of the most ambitious projects in the scientific history — the Human Genome Project. The Human Genome Project is a research effort undertaken to sequence all of our DNA and locate within it all of the functionally important sequences, such as genes. That is, the project seeks to determine the sequence of all 3.3 billion nucleotides of the human genome and to map the location of every gene on each chromosome. Information from the project will provide insight into our evolutionary past, genome organization, gene expression, and cell growth. The Human Genome Project linked more than 20 scientific laboratories in six countries. By 2001, the draft sequence of the human genome appeared in two landmark papers in the science journals Science and Nature. The high-quality sequence was completed in 2003 — two years ahead of schedule.... Scientists with the Human Genome Project were surprised by some of the discoveries they made, including the following: 1. Only about 2 percent of the human genome codes for proteins. 2. Chromosomes have unequal distribution of exons — sequences of nucleotides that are transcribed and translated. 3. The human genome is smaller than previously estimated. The human genome has only about 20,000 to 25,000 protein-coding genes — far fewer than the 100,000 originally estimated. Scientists now know that RNAs are not used only for translating DNA into proteins. Many RNAs are involved in regulating gene expression. 4. The exons of human genes are spliced in many ways, allowing the same gene to encode different versions of a protein. An organism's complete set of proteins is called its proteome. The human proteome is quite complex. 5. About half of the human genome arises from the shuffling of transposons, pieces of DNA that move from one chromosome location to another. Transposons appear to have no specific role in development or physiology. 6. There are about 8 million single nucleotide polymorphisms (SNP), unique spots where individuals differ by a single nucleotide. SNPs are important for mapping the genome in more detail, and in the identification of human disease genes. | — John H. Postlethwait, Janet L. Hopson, Modern Biology | Indexes/09 |
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Exxon human genetic connection in many ways, to make the same version of the gene encoding a protein. The full set of creatures called the protein-protein group.
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