We have discovered that less than 10 percent of the human genome encodes proteins and that what we have called “junk DNA” carries out important functions. We have gained an appreciation for the importance of noncoding RNAs, including piRNAs, microRNAs and lincRNAs. With regard to mutations, researchers have identified approximately 4,000 genes that cause genetic diseases. Among them are not only single-gene Mendelian disorders but also complex diseases such as cancer.
Progress in genome sequencing has not benefitted only researchers; farmers and pet owners have profited as well. Besides making a difference in agriculture, sequencing the genomes of domestic animals enriches our knowledge of conserved evolutionary pathways and genetic mechanisms of disease in those animals and in humans. Also, sequencing the genomes of disease-causing organisms is very important for the medical and veterinary fields.
Many of the achievements we have accomplished over the last decade were inconceivable at its beginning. However, many projects once considered overly ambitious now appear reasonable. For example, for years the thousand-dollar genome project sounded like science fiction; yet now the expectations are even higher, and we look to the day when we can sequence our own personal genomes for a more affordable price.
There remains a huge amount of work ahead of us. Although it may have seemed that the final sequence of the human genome had been determined in 2006, it is not yet complete. Human DNA fragments are still being sequenced, resequenced and analyzed. The genomic databases will be updated with the revised sequences. And there are many projects to complete, including characterization and cataloging of all transcript variants and epigenomic modifications as well as all intermolecular interactions between DNA, RNA and proteins.
We have made great progress in understanding the molecular mechanisms of diseases and developing diagnostic tools and effective treatments. Thanks to advances in genomic sequencing, we are moving away from the chemotherapy era and toward personalized medicine. But we cannot rest comfortably on our laurels, because, the more we learn in the post-genomic era, the more we realize how much more there is to know and explore in our instruction book.
- 1. The Human Genome Project Completion: Frequently Asked Questions. http://www.genome.gov/11006943 (Accessed October 2011).
- 2. Mardis, E.R. A decade’s perspective on DNA sequencing technology. (2011) Nature. 470, 198 – 203.
- 3. Lander, E.S. Initial impact of the sequencing of the human genome. (2011) Nature. 470, 187 – 197.
Roza Selimyan (email@example.com) is a research scientist at the National Institute on Aging.