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A Botanist in Molecular Biology

Why study "jumping genes" of corn?

Flowers with colored stripes, indicative of variegation in gene expression, have always fascinated me. As a child I was an avid gardener, requesting bushes and bulbs for birthday gifts; my favorites were always striped. Now that I'm a plant molecular biologist, I know that transposable elements Oumping genes) are the main cause of this variegation.

Developmental control is reflected in [1] timing: jumping genes are inactive in dividing cells but highly active later in development, and [2] differentiated state: in body cells, these genes jump out but in meiotic cells they jump in. We are analyzing this in maize using a combination of biochemistry and molecular biology.

At the level of plant:enviromnent interaction, we see activation of jumping genes by stresses such as ultraviolet radiation. Here the environment can act as an on-off switch.

Virginia Walbot, Professor, Stanford University

[Note: "jumping genes, " which are now widely known in animals as well as plants, were first discovered in 1950 by Barbara McClintock who won a Nobel prize in 1983 for her pioneering work in corn genetics.]

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