Biography 36: Thomas Dean Sargent (1953- )
Tom Sargent was born in Indianapolis, Indiana, (the same year as DNA). As a child he was always interested in science. When he was twelve years old, a family friend gave him the first edition of James Watson's textbook Molecular Biology of the Gene. Sargent pored over the text for months studying concepts that were meant for college-level students.
Sargent found biology so fascinating he majored in the subject at Indiana University. When he graduated he went to the California Institute of Technology for graduate work. During this time, gene cloning was a "new" technology and the arrival at Caltech of Tom Maniatis, who was the first to clone a mammalian gene, inspired many graduate students including Sargent to switch to gene cloning projects. Sargent finished his Ph.D. in 1981 by cloning and characterizing a rat serum albumin gene.
While at Caltech, Sargent and others, including Mark Davis and David Cohen, became interested in differential gene expression. For post-doctoral work, Sargent looked for an organism where he could easily make libraries of genes that were being expressed at different times in development. He sat in on a talk by Igor Dawid who was using frog embryos to study development. Sargent approached Dawid who hired him immediately as a post-doc. They developed the subtractive library system using frog mRNAs almost concurrently with Davis and Cohen, who used a similar method to look at T-cell specific gene expression. Sargent and Dawid published their results first. However, because so few genes had been cloned at the time, there weren't very many identifiable clones in their library; there were a number of "unknowns" and some epidermal keratin genes. Since then, the "unknowns" have been identified as being homeobox and other types of regulatory genes. Sargent has been and still works on epidermal development - the first tissues to form in frogs.
Sargent is currently Chief Research Microbiologist in the Section on Vertebrate Development in the Laboratory of Molecular Genetics, NICHD, NIH. He also teaches genetics at George Washington University. In his spare time, Sargent indulges in his hobby of wood-working.
Tom Sargent did some of the first differential gene expression studies using cDNA subtraction.
gene expression studies, differential gene expression, specific gene expression, frog embryos, molecular biology of the gene, serum albumin, tom sargent, rat serum, tom maniatis, james watson, thomas dean, mammalian gene, david cohen
- ID: 16755
- Source: DNALC.DNAFTB
Igor Dawid did some of the first differential gene expression studies using cDNA subtraction.
Sargent's gene library and comparisons with today's gene chips.
Figure from Sargent and Dawid's differential expression experiment in frog embryos.
Stanley Cohen talks about the challenge of isolating and studying individual genes.
Drosophila embryo showing the expression of hairy (yellow), a pair rule gene.
Igor Dawid and Thomas Sargent explain how they developed subtractive mRNA hybrization to find genes expressed by different cell types. Pat Brown and Steve Fodor show how genomes can be screened with DNA arrays and GeneChips™
Why use other animal models to study development?
David Botstein discusses how identifying the molecular mechanisms of cancer will lead to the development of improved therapies.
Professor James Eberwine explains that gene expression within a cell is dynamic - changing in various ways as a cell ages.
Part I: Theories on how organisms end up with differentiated cells.