scan0066.jpgDr. J. Herbert Taylor

In memorium 1916 – 1998

Robert O. Lawton Distinguished Professor Emeritus
Member, National Academy of Sciences (1977)
Ph.D. University of Virginia, 1944

Dr. J. Herbert Taylor was director of the Institute for Molecular Biophysics and recipient of the highest honor Florida State University can bestow upon its faculty, the Robert O. Lawton Distinguished Professor award. Taylor’s career spanned more than 50 years, during a time of phenomenal change in the fields of genetics and cell biology. His groundbreaking contributions to the knowledge of chromosome structure and reproduction produced many methods now standard in genetics. Taylor’s early work in the mid-1950’s helped to prove that DNA was the genetic material of the chromosome, by demonstrating that a radioactive label incorporated into DNA could be visualized in the autoradiograms of chromosomes.

He was among a group of 16 scientists who founded the American Society of Cell Biology in 1960. He published more than 100 papers on chromosome structure and reproduction. In recognition of a lifetime of work, he was elected to the National Academy of Sciences in 1977. The methods Taylor developed with his wife and colleague, Shirley Taylor, revolutionized the study of chromosomes. As stated in the dedication of the 2006 Cold Spring Harbor Press text book on DNA Replication: “Taylor comes as close as anyone to being the father of the field.”

J. Herbert Taylor Fund

From the Florida State University Biological Science Website:

Major Research Accomplishments of J. Herbert Taylor

  • Demonstrated the labeling with 3H-thymidine of the two DNA subunits of chromosomes and their semiconservative segregation during cell division (1956-57); first evidence for semiconservative replication of DNA.
  • Found the opposite polarity of the two subunits of chromosomes, indicating their analogy to the two chains of the Watson-Crick helix (1958-59).
  • Demonstrated the pattern of labeling of chromosomes over the cell cycle, including the discovery of the late-replicating X chromosome in mammals (1960).
  • Demonstrated that physical exchanges between homologous chromosomes occur during meiosis (1965).
  • Found that replication of DNA in mammalian chromosomes occurs by the production of small segments and later showed that some segments contain ribonucleotides (1969-1973).
  • Isolated and partially characterized the replication complex from mammalian cells in culture (1973-1977).
  • Obtained evidence concerning the kinetics and regulation of initiation in highly synchronized cells at the beginning of S phase. Showed that potential sites are available at 4-micron intervals along the DNA but that, in the normal cycle of cultured fibroblasts, only one in 15-20 of the potential origins is actually used in initiation of DNA replication (1973-1977).
  • (In collaboration with Shinichi Watanabe, graduate student) Cloned many EcoRI segments of Xenopus DNA into an Escherichia coli plasmid and tested these for origins of replication by injecting the supercoiled recombinant plasmids into unfertilized Xenopus eggs. Some sequences function as origins. A 505-base-pair segment containing an origin was sequenced, and experiments were continued to determine the sequences at functional origins (1980-1986).
  • (In collaboration with Karin Sturm and R. Alfred McGraw) Demonstrated by sequencing DNA that there are differences in modification (methylation) of satellite DNA’s in cells of various differentiated bovine tissues. Sperm and chorion are methylated at few sites compared to thymus, brain, liver, and kidney cells (1981-1990).

Selected Publications

Taylor, J. H. 1953. Intracellular localization of labeled nucleic acid determined with autoradiographs. Science 118: 555-557.

Taylor, J. H., P. S. Woods, and W. L. Hughes. 1957. The organization and duplication of chromosomes as revealed by autoradiographic studies using tritium-labeled thymidine. Proc. Natl. Acad. Sci. USA 43: 122-128.

Taylor, J. H. 1989. DNA synthesis in chromosomes: implications of early experiments. BioEssays 10: 121-124.

Taylor, J. H. 1990. Chromosome reproduction: units of DNA segregation. BioEssays 12: 289-296.

Taylor, J. H. 1991. My favorite cells with large chromosomes. BioEssays 13: 479-487.

Taylor, J. H. 1991. Tritium-labeled thymidine and early insights into DNA replication and chromosome structure. Trends in Biochemical Sciences 19: 479-487.