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'Genomics' is the study of an organism's entire genome. In contrast, the investigation of single genes, their functions and roles, something very common in today's medical and biological research, and a primary focus of molecular biology, does not fall into the definition of genomics, unless the aim of this genetic, pathway, and functional information analysis is to elucidate its effect on, place in, and response to the entire genome's networks.
Genomics can be said to have appeared in the 1980s, and took off in the 1990s with the initiation of genome projects for several biological species. A major branch of genomics is still concerned with sequencing the genomes of various organisms, but the knowledge of full genomes has created the possibility for the field of functional genomics, mainly concerned with patterns of gene expression during various conditions. The most important tools here are microarrays and bioinformatics. Study of the full set of proteins in a cell type or tissue, and the changes during various conditions, is called proteomics.
In 1972, Walter Fiers and his team at the Laboratory of Molecular Biology of the University of Ghent (Ghent, Belgium) were the first to determine the sequence of a gene: the gene for Bacteriophage MS2 coat protein.^[1]
In 1976, the team determined the complete nucleotide-sequence of bacteriophage MS2-RNA.^[2]
The first DNA-based genome to be sequenced in its entirety was that of bacteriophage Φ-X174; (5,368 bp), sequenced by Frederick Sanger in 1977^[3].
The first free-living organism to be sequenced was that of ''Haemophilus influenzae'' (1.8 Mb) in 1995, and since then genomes are being sequenced at a rapid pace. A rough draft of the human genome was completed by the Human Genome Project in early 2001, creating much fanfare.
As of January 2005, the complete sequence was known of about 1,000 viruses, 220 bacterial species and roughly 20 eukaryote organisms, of which about half are fungi.
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Most of the bacteria whose genomes have been completely sequenced are problematic disease-causing agents, such as ''Haemophilus influenzae''. Of the other sequenced species, most were chosen because they were well-studied model organisms or promised to become good models. Yeast (''Saccharomyces cerevisiae'') has long been an important model organism for the eukaryotic cell, while the fruit fly ''Drosophila melanogaster'' has been a very important tool (notably in early pre-molecular genetics). The worm ''Caenorhabditis elegans'' is an often used simple model for multicellular organisms. The zebrafish ''Brachydanio rerio'' is used for many developmental studies on the molecular level and the flower ''Arabidopsis thaliana'' is a model organism for flowering plants. The Japanese pufferfish (''Takifugu rubripes'') and the spotted green pufferfish (''Tetraodon nigroviridis'') are interesting because of their small and compact genomes, containing very little non-coding DNA compared to most species.
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The mammals dog (''Canis familiaris''),
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brown rat (''Rattus norvegicus''), mouse (''Mus musculus''), and chimpanzee (''Pan troglodytes'') are all important model animals in medical research.

Contents

See Also

References

See Also

★ Computational genomics

★ Nitrogenomics

References

1. Min Jou W, Haegeman G, Ysebaert M, Fiers W., Nucleotide sequence of the gene coding for the bacteriophage MS2 coat protein, Nature. 1972 May 12;237(5350):82-8
2. Fiers W et al., Complete nucleotide-sequence of bacteriophage MS2-RNA - primary and secondary structure of replicase gene, Nature, 260, 500-507, 1976
3. Sanger F, Air GM, Barrell BG, Brown NL, Coulson AR, Fiddes CA, Hutchison CA, Slocombe PM, Smith M., Nucleotide sequence of bacteriophage phi X174 DNA, Nature. 1977 Feb 24;265(5596):687-95
4.
''Nationalencyklopedin'', encyclopaedia in Swedish, the article ''Genom''. Web edition, available only to subscribers

5.
BBC article ''Human gene number slashed'' from Wednesday, 20 October, 2004

6.
CBSE News, Thursday October 16, 2003

7.
NHGRI, pressrelease of the publishing of the dog genome