By Gail Gallessich

A tiny, predatory protozoan has yielded the secrets of its genome in a project spearheaded by a veteran research scientist at UC Santa Barbara. The results were published last month in the prestigious, peer-reviewed journal, the Public Library of Science Biology. One unusual aspect of the UCSB component of this study was the participation of numerous undergraduate students over the years, many of whom have since gone on to graduate schools, medical programs, or obtained jobs with biotech companies.

The newly published Tetrahymena genome sequence, which reveals thousands of genes that are shared by the protozoan and humans, confirms it to be an important model organism for biomedical research.

The publication of this project caps more than a decade of work by the research group of Eduardo Orias, professor of molecular, cellular, and developmental biology. Jonathan A. Eisen at the Institute for Genome Research in Rockville, Md., directed the overall project. Orias’s group mapped hundreds of genetic and physical landmarks in the Tetrahymena genome.

Once the genome sequence became available, the maps provided the most direct verification of the high degree of accuracy and completeness of the genome sequence, according to the article.

“The published genome sequence represents a valuable scientific resource for fundamental, biomedical and biotech research,” said Orias. “T. thermophila is a very user-friendly organism for scientific experimentation.”

Many discoveries with important applications to human biology and medicine have already been made with this organism. These include:

• the discovery of catalytic RNAs (a Nobel Prize-winning discovery);

• dynein (the first known nanoscale cell motor);

• the structure of telomeres (specialized sequences at the ends of chromosomes);

• the machinery that maintains telomeres (whose regulation protects cells from cancer and is connected to aging);

The genome sequence shows that Tetrahymena contains over 27,000 genes, a number surprisingly similar to that of genes found in the human genome. Some shared genes are known to cause hereditary disease when mutated, and T. thermophila provides an excellent model for quick and relatively inexpensive investigation of their functions.

Says Anthony D. Carter, a program director with the National Institutes of Health, “Publication of the Tetrahymena genome marks the culmination of a remarkable collaboration within the research community… (Complete description) of its genome is likely to lead to further fundamental insights into how cells work.”

Orias has long been a strong supporter of undergraduate research. Eleven undergraduate co-authors, including three first co-authors, are on 11 of the 26 papers published in peer-reviewed journals by his group over a dozen years.

The systematic mapping of the Tetrahymena genome was started by a very talented and committed UCSB undergraduate, Jason Brickner (now an assistant professor at Northwestern). Altogether, more than 60 UCSB undergraduates have worked on the genetic and physical mapping project since 1994.