The Genome Revolution

In recent months, genome sequencers have sequenced the potato genome, the cod genome, and even the marijuana genome. These are just a few of the large number of genomes that have been sequenced over the last decade.

Genome sequencing started over 30 years ago with the sequencing of bacteriophages (viruses that infect bacteria) MS2 in 1976 and phi-X174 in 1977. Their genomes are very short, 5386 RNA bases for MS2 and 5386 DNA bases for phi-X174. A cellular organism was not sequenced until nearly 20 years later; it was Haemophilus influenzae in 1995. That bacterium has 1.8 million base pairs (Mbp). But a year later, the first eukaryote was sequenced, the well-known yeast Saccharomyces cerevisiae, at 12.1 Mbp. The lab nematode Caenorhabditis elegans, with 100 Mbp, was sequenced in 1998, and the lab fruit fly Drosophila melanogaster, at 130 Mbp, in 2000.

Around that time was the Human genome Project, which was big and controversial, with some people questioning the massive expenditure on this effort. Our genome has 3.2 billion base pairs, and it took some years to sequence and assemble back then. But sequencing technology has continued to improve, with one sequencing center, the DOE Joint Genome Institute now being able to get raw sequence data at a rate of 5 human genomes per day.

Not surprisingly, the majority of genomes sequenced have been of prokaryotes; at least 1700 prokaryote genomes have now been sequenced. However, a sizable number of eukaryote genomes have now been sequenced, including genomes of familiar species like chimps, rhesus monkeys, mice, rats, dogs, cats, bovines, horses, chickens, zebrafish, sea urchins, honeybees, aphids, bread mold, rice, corn, and grapes.

But among the genomes sequenced have been more human ones, like those of genome sequencer Craig Venter in 2007 and biologist James Watson, co-discoverer of the structure of DNA, in 2008. James Watson’s genome took only 2 months to sequence. There are more to come, and a field of “personal genomics” has been emerging. In a few years, it may be possible to get one’s genome sequenced for a few thousand dollars or some equivalent in other currencies. One may then be able to find what diseases that one may be vulnerable to. One may even be able to also do that for one’s pets.