TSRI scientists clone gene that regulates circadian rhythms...( La Jolla CA August 4 2000 Scient...)

La Jolla, CA, August 4, 2000 Scientists at The Scripps Research Institute (TSRI) have cloned a gene that regulates circadian rhythms in plants, providing an increased understanding -- on a molecular level -- of the processes that enable organisms to anticipate and adapt to daily variations in the environment. According to Steve Kay, Ph.D., Professor of Cell Biology and an author of the study, "The work moves scientists in the direction of understanding how this gene helps plants keep accurate track of time, an extremely important capacity for organisms that are completely dependent on the daily cycle of light."

Further, researchers believe that understanding internal "clocks" in plants might also elucidate how clocks work in other species, including humans.

The study, "Cloning of the Arabidopsis Clock Gene TOC1, an Autoregulatory Response Regulator Homolog," appears in today's issue of Science. Its authors are Drs. Carl Strayer, Tokitaka Oyama, Thomas F. Schultz, Ramanujam Raman, David E. Somers, Paloma Mas, Satchidananda Panda, Joel A. Kreps, and Steve A. Kay.

Many biological processes -- the growth of fungi, activity of insects, changes in blood pressure in humans -- fluctuate daily, rising and falling at predictable times of day or night. They do so because the organisms possess internal clocks that time the rhythms. Plants, for example, use their clocks to get a jump on the day, gearing up their photosynthetic machinery and raising their leaves just before dawn. They also use their clocks to measure day length and in that way anticipate changes in the seasons a system that determines when they shed their leaves or produce seeds or tubers in the fall, or make flowers or fruit in the spring.

Scientists have provided evidence of the existence of internal clock mechanisms by placing organisms in isolation chambers where they are prevented from seeing day/night cycles and in spite of this, their rhythms recur approximately every 24 hou
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Contact: Robin B. Goldsmith
rgoldsmi@scripps.edu
858-784-8134
Scripps Research Institute
3-Aug-2000