TIGR Leads New Project to Sequence Tetrahymena Genome

Small Genome Variations Account For Wide Range of Diseases, Victims

April 9, 2003

Two new federal grants will allow scientists to sequence and analyze the genome of the single-celled model organism Tetrahymena thermophila in a collaborative effort that will benefit a wide range of research, from experimental cell and molecular biology to comparative and functional genomics.

The Tetrahymena sequencing project is being led by scientists at The Institute for Genomic Research (TIGR), in Rockville, MD, in collaboration with the University of California, Santa Barbara, and Stanford University. The National Institute of General Medical Sciences (NIGMS) and the National Science Foundation (NSF) recently awarded grants totaling $6.43 million to support the project.

Tetrahymena is a member of a group of organisms called the ciliates, which are characterized by hair-like projections called cilia that allow them to swim. Tetrahymena's many cilia give it the appearance of a tiny hairy beast. Like humans, ciliates are eukaryotic organisms (their DNA is packaged into a structure called a nucleus).

"Tetrahymena is an excellent model system for studying the biology of all eukaryotes, including humans," says Jonathan Eisen, Ph.D., TIGR's principal investigator for the project. "And the use of Tetrahymena as a model will be greatly facilitated by deciphering its complete genome sequence."

Eduardo Orias, Ph.D., a leading Tetrahymena researcher at UC Santa Barbara, will provide project liaison with the ciliate research community. He says the new project "will greatly accelerate the high quality fundamental and biomedical research that is currently in progress using ciliates, and will open up exciting new lines of investigation."

Tetrahymena has been used as a model system for studying the biology of ciliates and of all eukaryotes. Major discoveries based on studies of Tetrahymena include the Nobel-prize winning discovery of RNA-mediated catalysis and the structure and function of telomeres, which are caps on the ends of chromosomes in eukaryotes. Recent studies involving Tetrahymena also have led to breakthroughs in understanding the role of chromatin in gene activity and to demonstrating a novel function for small RNAs in gene silencing and in DNA rearrangement.

"Biomedical research using Tetrahymena as a model organism has yielded major advances in a surprisingly broad range of areas," said Judith Greenberg, Ph.D., acting director of NIGMS. "We expect the sequencing of the Tetrahymena genome to be of great benefit to the scientific community and to have significant impact on our understanding of how cells work."

Matthew Kane, Ph.D., the National Science Foundation's program director for Molecular and Cellular Biosciences, says, "The results of the genome sequencing project will tell us much about how complex cells function and will also provide insight into the diversity and history of life on Earth."

This project will promote unrestricted and user-friendly access to the Tetrahymena thermophila genome sequence, Eisen said, by releasing the data immediately and by creating two interlinked database resources for researchers: a database of genomic information and annotation at TIGR and a manually curated Tetrahymena Genome Database at Stanford University.

The three-year grant from NIGMS for Tetrahymena sequencing and analysis totals $3.87 million, and the two-year grant from the NSF totals $2.56 million. The NIGMS grant includes funds for database development.