Genomics

Genomics
The scientific field of mapping, sequencing and analyzing genomes is now known as genomics, a term that has come into wide use only in the last decade. Some researchers divide genomic analysis into “structural genomics” (mapping and sequencing) and “functional genomics” (development of genome-wide or system-wide experimental approaches to understand gene function).

In the 1970s Allan Maxam and Walter Gilbert in the United States and Frederick Sanger in England reported practical techniques for determination of the sequence of bases in DNA. By 1984 and 1985 scientists proposed to sequence and map the entire human genome, an effort that came to be known as the Human Genome Project. It was a most ambitious undertaking: the genome was estimated at 50,000 to 100,000 genes and regulatory subunits encoded in a linear sequence of about 3 to 6 billion pairs of bases. Using the techniques available in 1988, it would have taken until the year 2700 to sequence the genome completely, but biologists then expected that technical improvements would make it possible to finish in the twenty-second century. In fact, development and improvement of automated sequencers, as well as participation of numerous laboratories, have lowered estimates for completion to two to three years.

Four thousand human diseases, such as cystic fibrosis and Huntington’s chorea, are known to result from defects in single genes. About 200 disease-associated genes have already been identified using location and sequence information supplied by the Genome Project. These studies will lead to new diagnostic tests, treatments, possible preventive strategies, and advances in the molecular understanding of these diseases. In addition, the project includes sequencing of genomes of other organisms, such as bacteria, yeast, fruit flies, and nematodes (Caenorhabditis elegans). Not only does this provide information for researchers on those species, it provides approaches to investigations of the striking similarities (homologies) of genes across a range of species.