UB prof is key player in discovery of third branch of life on earth

By LOIS BAKER
News Services Editor

Joseph M. Merrick conducted computer analysis of the 1,738 genes identified in the microbe Methanococcus jannaschii. Researchers on the team had used gene-sequencing to confirm that archaea, the group of organisms to which the microbe belongs, constitutes a different branch of life from bacteria and eucarya, the latter including plants, animals, fungi and protozoa.

The study of Methanococcus jannaschii appeared in the Aug. 23 issue of the journal Science.

The discovery has been heralded as one of the major basic science developments of our time; a milestone in mankind's drive to understand the nature of life, its diversity and its evolution.

Merrick was part of the research team that sequenced the entire genome (DNA) of M. jannaschii, which lives on the edge of a volcanic vent on the floor of the Pacific Ocean in a water temperature just below the boiling point. His role was to carry out computer analysis of the genes identified in an effort to define their metabolic role. Some of the genes were similar to those found in bacteria, while others were more similar to those found in the cells of higher organisms, the study noted.

The majority, however, are new to science and biology. "Only 38 percent could be assigned a cellular role with some degree of confidence, which means we haven't a clue what two-thirds of the genes in this organism do," Merrick said. "The challenge in the future will be to discover functions of the genes that have no counterparts in existing genetic databases. It is possible that new metabolic pathways, new control mechanisms and perhaps even new signaling processes will be revealed."

Merrick, a microbial physiologist, spent 18 months at The Institute for Genomic Research in Gaithersburg, Md., one of the three centers involved in the gene-sequencing project and the site where the software with which he worked was developed. The director of the center is J. Craig Venter, a former UB professor who supervised the work.

Funded by the U.S. Department of Energy, the research is thought to have vast implications for biological science, Merrick said. "Besides the basic science interest, there is a practical side," he added. "This organism grows at very high temperatures with an optimum temperature of 85 degrees Centigrade. At this temperature, most proteins found in other organisms would be inactivated.

"The genes encode for hundreds of enzymes that are stable at high temperature and will likely find use as a catalyst in chemical, food and pharmaceutical processes."

In addition, the organism is a potentially renewable power source, Merrick said. "M. jannaschii uses simple nutrients, such as hydrogen and carbon dioxide, to grow, and as a by-product, it generates methane. Thus, this organism provides the possibility of generating large supplies of a safe and renewable source of energy."

Merrick also was involved in the study of the first bacterial genome to be sequenced and assembled, Haemophilus influenzae, as well as the second, Mycoplasma genitilium. Results of that research appeared in Science in July and October 1995, respectively.

He and another noted UB microbiologist, Philip T. LoVerde, recently received funding from UB's Multidisciplinary Research Pilot Project Program to initiate a gene-sequencing project on schistosomes, parasites that cause the tropical disease schistosomiasis. A grant for this work is pending with the World Health Organization.