Scientists can identify genes that carry out specific tasks in bacteria by mutating genes randomly in cell populations, selecting for individuals whose biological properties are altered by the mutation, and then identifying genes that are mutated in those individuals. However, similar procedures aimed at discovering genes having specific functions have not been practical in mammalian cells, which contain two separate copies of each gene. Inactivation of one copy ordinarily will not produce detectable biological effects because the other copy will continue to function.

Stanley N. Cohen will discuss "reverse genomics," a genetic approach that has proved useful in discovering and characterizing mammalian genes that regulate cell proliferation and suppress tumorigenesis. In reverse genomics, scientists use "reporter genes," whose expression is controlled by DNA sequences linked to them, to investigate genetic regulatory mechanisms in both simple and higher organisms. Researchers can now directly isolate genes that specify functions of particular interest using reporter-gene-containing cassettes that can manipulate, as well as monitor, the expression of genes in mammalian chromosomes.

In November 1973, a paper published in the Proceedings of the National Academy of Science by Cohen and Herbert W. Boyer of the University of California revolutionized the disciplines of biology, chemistry and biotechnology. The paper described a methodology for propagating DNA, the hereditary material of all living cells, in foreign hosts. The invention of recombinant DNA methodology or "genetic engineering" by Cohen and Boyer created what has been called "the new genetics." With this invention, Cohen and Boyer showed how any DNA could be inserted into, and reproduced by, the genetic machinery of bacterial cells.

In subsequent experiments, Cohen showed that animal cell genes introduced into bacteria could function biologically in their new environment; thus, bacteria carrying human genetic information could now be engineered to churn out large quantities of human chemicals. For the first time, diseases could be treated with drugs nature expressly intended for the purpose.

The author of more than 270 scientific publications, Cohen has received numerous awards, including the National Medal of Science, the National Medal of Technology and the Albert Lasker Award for Basic Medical Research. He is a member of the U.S. National Academy of Sciences and a past chairman of its Genetics Section.

For additional information, please call Ms. Gloria Phipps at (212) 327-8967