On this day, 28 years ago, May 17, 1997 (April 11, 1997 in the lunar calendar), American scientists initially revealed the mystery of the mechanism of the biological clock. On May 17, 1997, researchers from Northwestern University in the United States discovered a gene that controls the biological clock of experimental mice, revealing for the first time the mystery of the mechanism of action of the mammalian biological clock. This is of great significance for understanding the operating mechanism of human own biological clock. A research team led by Joseph Takakash of Northwestern University reported in the May 17 issue of Cell that they found a key to controlling their biological clock by artificially cultivating experimental mice whose biological rhythm was disrupted. Chemical substance, and then identified a gene called the "clock" that determines the existence of this chemical. Takakhash and others first used drugs to mutate the sperm of male mice, and then used this mutated sperm to reproduce a new generation of experimental mice and place them completely in the dark, disrupting their biological rhythm and making their biological cycle longer than normal experimental mice. A few hours longer. After two years of experiments on 2400 experimental mice, Takakhash and others finally found the biological clock gene and named it "Clock". Under normal circumstances, this gene can produce a special "clock" protein composed of 855 amino acids, and through this protein, a total of about 10 genes that have not yet been determined by scientists that can specifically regulate biological rhythm. The mechanism of action of the biological clock has long been a scientific mystery. Scientists only know that the biological clock can control the sleep and awake cycles, hormone secretion, metabolic rate, body temperature and other physiological behaviors of various animals, including humans, but the composition of the biological clock and the form it uses to accomplish the above work has not been clarified. Scientists seeking to understand the structure of the biological clock have found genes related to the biological clock of simple organisms such as fruit flies and fungi in recent years, but have been unable to make breakthroughs in mammalian research. Takahash and others also found that clock proteins are found in almost every important part and organ in experimental mice.