About David M.Gilbert

Dr. David M. Gilbert came to Florida State University in 2006 as the campus’s first J. Herbert Taylor Distinguished Professor of Molecular Biology. As an undergraduate student at the University of California, San Diego, Dr. Gilbert became fascinated by aspects of gene regulation that cannot be accounted for by the sequence of bases in DNA. Taylor’s 1962 demonstration that the two different X chromosomes in females replicate at different times had a seminal influence on the direction that Gilbert pursued because these two chromosomes have the same DNA sequences yet the genes on one are active while those on the other are not.

While pursuing his PhD at Stanford University, Gilbert further probed the role of DNA replication in chromosome structure and function. He subsequently traveled to France to work with one of the top gene expression biologists in the world, and returned to the US to continue his studies of DNA replication.

In 1994 he started as an Assistant Professor at the State University of New York’s Upstate Medical University, where he received Upstate’s Presidential Award for Research by a Young Investigator, and was nominated to the Howard Hughes Medical Institute in 2005.

His research has been supported by the National Institutes of Health, the National Science Foundation, the American Cancer Society, the March of Dimes and the Stem Cell Research Foundation. He has also served as a member of the review panels for these same organizations and is a regular reviewer for numerous scientific journals. He has published more than 70 papers on chromosome structure and reproduction. Gilbert’s research is focused on precisely the same problems that intrigued Herb Taylor, and is a well-respected member of both the DNA replication and chromosome structure fields, a unique combination. It is no secret that Gilbert came to FSU in a large part “to honor and to be honored by the legacy of Herb Taylor.”

In 1960, J. H. Taylor demonstrated, using radioactive thymidine, that certain segments of chromosomes are replicated at specific times during S-phase; the silver grains show the areas where DNA replicated late during the cell cycle.
In 1984 as a beginning graduate student, D. Gilbert labeled cells with bromo-deoxy-uridine (BrdU) instead of radioactive thymidine and used a fluorescent antibody specific to the BrdU to highlight replicated regions; areas where DNA replicated late during the cell cycle are yellow; the remainder of the DNA is red. This nonradioactive procedure has now become the method of choice for visualizing sites of DNA synthesis.

Gilbert’s major research accomplishments:

  • 1986: In his first published study, Gilbert demonstrated that active and inactive genes with similar DNA sequences replicate at different times during the cell cycle, providing an explanation for their differential expression.
  • 1989: Gilbert’s doctoral thesis work probed what he saw as the primary knowledge vacuum in the field; understanding how replication can be regulated to duplicate different segments of chromosomes at different times. He published numerous studies revealing that DNA replication was considerably more complex than previously imagined from experiments with bacteria and viruses.
  • 1995: Gilbert demonstrated that the sites where replication begins are not determined by a specific sequence of nucleotide bases alone, but also require components that package DNA in the nucleus.
  • 1996: Gilbert discovered a specific time during the cell cycle at which cells choose where to begin replicating DNA; the Origin Decision Point (ODP).
  • 1999: Gilbert discovered that cells also choose when to replicate different segments at a specific time during the cell cycle; the Timing Decision Point (TDP). This and later work showed that the “where” and the “when” are determined at separate times and by distinct mechanisms.
  • 2004: Gilbert demonstrated that the temporal sequence in which segments of DNA are packaged into chromatin changes as stem cells turn into different cell types.