Tackling the hairy beast - Tetrahymena genome

Just thought I would put out a little self-promotional posting here on a paper we have published today on the genome of a very interesting organism called Tetrahymena thermophila. This organism is a single-celled eukaryote that lives in fresh water ponds.

This species has served as a powerful model organism for studies of the workings of eukaryotic cells. Studies of this species have led to some fundamental discoveries about how life works. For example, telomerase, the enzyme that helps keep the ends of linear chromsomes from degrading, was discovered in this species. This may not seem too important, but many folks think that degradation of chromosome ends in humans is involved in aging. Perhaps even more importantly, (to me at least) studies of this species were fundamental to the discovery that RNA can be an enzyme. This discovery of catalytic RNA revolutionized our understanding of how cells work and how life evolved. Tom Cech and Sidney Altman were given the Nobel Prize in 1989 for this discovery.

Many (including myself) believe that having the genome sequence of this species will further spur research and its use as a model organism. In addition, we believe that some of the findings we report in our paper will further cement the importace of this species. For example, this species, though single celed, encodes nearly as many proteins as humans and possesses many processes and pathways shared with animals but missing from other model single celled species.

The project that led to this publication was undertaken while I was at TIGR (The Institute for Genomic Research) and involved a collaboration among people at dozens of research institutions around the world. It all started in 2001 when Ed Orias and his colleagues sought to see if anyone at TIGR would be interested in putting in a grant to sequence this species' genome. I responded to the email saying I was interested, especially since I had interacted with multiple people who used this species as a model system (e.g., Laura Landweber at Princeton and Laura Katz at Smith). So I went to a FASEB meeting where the Tetrahymena Genome Steering Committee was meeting and discussed with them how TIGR might help sequence the genome. And after talking to other genome centers, they selected TIGR to put in a grant proposal with them.

We ended up getting funding from two grant proposals - one from NIGMS and the other from the NSF Microbial Genome Sequencing Program. The sequencing was done in a rapid burst at the new Joint Technology Center which TIGR shares with the Venter Institute. And then we spent ~1.5 years analyzing the sequence data (and assemblies) that came out and in the end we fortunately were able to get our paper into PLoS Biology, in my opinion the best place available to publish biology research.

Importantly PLoS Biology is Open Access which allows anyone anywhere to read about our work. This goes well with the free and open release we made of the genome sequence data. In fact, many people published papers on the genome before we did (sometimes scooping us). In the end, I accepted the risks of releasing the genome data with no restrictions inexchange for advancing research on this organisms. I think this risk was well worth it as we still got our big paper published and the field has advanced more rapidly than if we had not released the data.

Other links that may be of interest to people:

• The Tetrahymena Genome Database
• Tetrahymena Web Links
• Ed Orias' Tetrahymena Site
• Tetrahymena site at TIGR

Eisen, J., Coyne, R., Wu, M., Wu, D., Thiagarajan, M., Wortman, J., Badger, J., Ren, Q., Amedeo, P., Jones, K., Tallon, L., Delcher, A., Salzberg, S., Silva, J., Haas, B., Majoros, W., Farzad, M., Carlton, J., Smith, R., Garg, J., Pearlman, R., Karrer, K., Sun, L., Manning, G., Elde, N., Turkewitz, A., Asai, D., Wilkes, D., Wang, Y., Cai, H., Collins, K., Stewart, B., Lee, S., Wilamowska, K., Weinberg, Z., Ruzzo, W., Wloga, D., Gaertig, J., Frankel, J., Tsao, C., Gorovsky, M., Keeling, P., Waller, R., Patron, N., Cherry, J., Stover, N., Krieger, C., del Toro, C., Ryder, H., Williamson, S., Barbeau, R., Hamilton, E., & Orias, E. (2006). Macronuclear Genome Sequence of the Ciliate Tetrahymena thermophila, a Model Eukaryote PLoS Biology, 4 (9) DOI: 10.1371/journal.pbio.0040286