Genome

Lore & Background

The term genome was created in 1920 by Hans Winkler, professor of botany at the University of Hamburg, Germany. The Oxford Dictionaries and Online Etymology Dictionary suggest the name is a blend of the words gene and chromosome. The first genome to be sequenced was that of the virus φX174 in 1977; the first genome sequence of a prokaryote (Haemophilus influenzae) was published in 1995; the yeast (Saccharomyces cerevisiae) genome was the first eukaryotic genome to be sequenced in 1996. The Human Genome Project was started in October 1990, and the first draft sequences of the human genome were reported in 2001; the finished sequence was completed in 2003.

Reader's Guide

The genome is a foundational concept in molecular biology and genetics, representing the complete set of genetic instructions for an organism. Its study, genomics, has enabled the sequencing of many organisms, from viruses to humans. The term's origin in 1920 predates the molecular era, but the first viral genome sequence in 1977 and subsequent prokaryotic and eukaryotic sequences established the field. The Human Genome Project's draft in 2003 marked a milestone, though the definition of genome remains nuanced: it typically refers to nuclear DNA in eukaryotes, but includes organelle genomes in mitochondria and chloroplasts. Viral genomes can be RNA or DNA, and prokaryotic genomes often include plasmids. The concept of ploidy and the inclusion of sex chromosomes in reference genomes (e.g., one copy of each autosome plus X and Y in humans) are important technical details. Noncoding sequences, including repetitive DNA, make up the majority of many eukaryotic genomes, such as 98% of the human genome.

Did You Know?

• The first genome sequenced was that of the virus φX174 in 1977.
• The term genome was created in 1920 by Hans Winkler.
• Noncoding sequences make up 98% of the human genome.
• The first draft sequences of the human genome were reported in 2001.