New sequence of maize genome. The ten chromosomes of the maize genome are shown here, with concentric circles reflecting various characteristics of the genome. Thin ribbons connect duplicate regions in the maize genome, thereby revealing large related segments and reflecting the maize genome's complicated structure.

Credit: Image courtesty of Science/AAAS.

Corn is an important crop--with about $47 billion dollars worth of corn grown on about 86 million acres of U.S. farm land, according to 2008 figures.

Credit: Patrick S. Schnable, Iowa State University

A cross between two inbred plants (left and right) produces a more vigorous and productive offspring (center), with significant practical advantages. The new maize genome sequence is expected to lead to a full understanding of the genetic basis for maize growth and development. This information will be used to tailor maize varieties to thrive in new environments and to generate new products.

Credit: Jun Cao and Patrick S. Schnable, Iowa State University, reprinted by permission from Springer-Plant Sciences.

The hybrid strain of maize (center) produced by a cross between a known as B73 (left), which is the strain that was sequenced, and a strain of maize known as Mo17 (right) is bigger than both parents.

Credit: David Cavagnaro with assistance from Lois Girton and Marianne Smith.

Maize has long served as a model organism for studying genetics because many of its important genetic traits are expressed in kernels, and so are easily observed. While studying maize genetics more than 60 years ago, Barbara McClintock discovered mobile pieces of DNA, called transposable elements. Transposable elements affect the color of maize kernels and are responsible for the purple-colored sectors and spots shown in this 1949 ear of maize from the McClintock collection.

Credit: Robert Martienssen, Cold Spring Harbor Laboratory.

Researchers published their findings in the Nov. 20, 2009, issue of the journal Science.

Credit: Copyright AAAS 2009