What is a genome?

A genome is the entire DNA in an organism, including its genes. Genes carry information for making all the proteins required for all organisms. These proteins will determine how an organism looks, how it might fight infection or diseases, and possibly its behavior.

DNA is made up of four similar chemicals called bases that are abbreviated A (adenine), T (thymine), C (cytosine), and G (guanine). These bases are repeated many times throughout a genome. For example, it is estimated that the human genome has more than 3.2 billion pairs of bases. The order of As, Ts, Cs, and Gs is critical. The order of these letters dictates whether an organism is a human or another species, such as a fruit fly or mouse.

This is why scientists are interested in sequencing other genomes. Understanding and comparing the DNA of other organisms will help scientists learn more about evolution and human life.

How can we use genomic data?

To the average person, this vast code of As, Ts, Gs, and Cs is overwhelming. However, a map of the human genome offers unlimited potential to scientists. Some of the benefits of genome research include:

• Molecular Medicine: improved diagnosis of disease, earlier detection of genetic predispositions to disease, gene therapy, and pharmacogenomics (custom drugs)
• Microbial Genomics: vaccines, antibiotics, and diagnostics for infectious diseases, new energy fuels (biofuels); environmental monitoring to detect pollutants; protection from biological and chemical warfare; and safe, efficient toxic-waste cleanup
• Risk Assessment: assessment of health damage risks caused by radiation exposure, chemicals and cancer causing toxins
• DNA Forensics: identification of potential suspects whose DNA may match evidence left at crime scenes; exoneration of persons wrongly accused of crimes; establishment of paternity and other family relationships
• Bioarchaeology, Evolution, and Human Migration: study of evolution through germline mutations in lineages and of population migration based on mitochondrial DNA; and comparison of breakpoints in the evolution of mutations with ages of populations and historical events
• Agriculture, Livestock Breeding, and Bioprocessing: production of crops resistant to disease, insects and drought, as well as healthier, more productive, disease-resistant farm animals