Biography 36: Igor Dawid (1935- )
Igor Dawid was born in Central Europe in what was Romania but is now part of Ukraine. There wasn't any defining event or moment that set him on a scientific career, especially since there wasn't too much science taught in his high school. However, he recognized that science was interesting and important. After World War II, Dawid went to Vienna to study.
The University of Vienna didn't have a biochemistry curriculum and given a choice between pure biology or chemistry, Dawid chose chemistry. He finished a Ph.D. in chemistry in 1960. By this time, he realized that to further his career, he needed to work in the United States. With help from his Ph.D. advisor, he obtained a post-doctoral position at the Massachusetts Institute of Technology. It was here that he pursued a growing interest in biochemistry. He read an article in a journal that talked about the isolation of a "factor" that induced tissues to change their fate. Even though the article was retracted a few months later, Dawid's interest was piqued and he decided to go to Woods Hole for a course in this growing field of tissue-specific genes.
At Woods Hole, Dawid met James Ebert, the director of the Carnegie Institute and later the director of Woods Hole. Ebert invited Dawid to work at the Carnegie and in 1962, Dawid became a Fellow and worked with Don Brown. Brown was using the traditional embryologist's model, frogs, to study development. Frog embryos are large and changes are easily visible. Also, a lot was known about the various stages of development. Dawid adopted frogs as a model system and continued to use them when he moved to the National Institutes of Health in 1978.
Tom Sargent joined his lab in the early '80s. And they began working on Sargent's idea of isolating differentially expressed mRNAs from different frog embryonic stages. The subtractive mRNA technique not only netted a lot of stage-specific mRNA, but worked surprisingly well in that the differential libraries had very little cross-stage contamination.
Dawid is currently the Acting Scientific Director of the National Institute of Child Health and Human Development. His lab in the Laboratory of Molecular Genetics Division works on differential gene expression in frogs and zebrafish.
Dawid has been the Editor-in-chief and now serves on the advisory board of the scientific journals Developmental Biology, and Proceedings of the National Academy. He has been the Associate Editor of other journals, Cell and Genes and Development. He enjoys classical music and is an opera buff.
Figure from Sargent and Dawid's differential expression experiment in frog embryos.
Tom Sargent did some of the first differential gene expression studies using cDNA subtraction.
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™
Sargent's gene library and comparisons with today's gene chips.
Why use other animal models to study development?
Drosophila embryo showing the expression of hairy (yellow), a pair rule gene.
Part I: Theories on how organisms end up with differentiated cells.
Part II: Theories on how organisms end up with differentiated cells.
DNA microarrays provide the means to analyze patterns of gene expression at different timepoints in a living cell.
Molecules that regulate development are similar in different organisms.