An international team led by researchers from the University of California, Davis (UC Davis), and the Cold Spring Harbor Laboratory (CSHL) has mapped the transposable elements, or transposons of maize. Transposons, called jumping genes because they move locations within a genome, was discovered in maize by Nobel-winning geneticist Barbara McClintock in the 1940s.

Until now, the exact location of transposons has been elusive, as they are difficult to sequence and assemble. Michelle Stitzer, graduate student at UC Davis, and maize geneticist Jeff Ross-Ibarra, worked with colleagues at CSHL and several universities and genome technology companies to create a new maize reference genome that includes the many complex repeat regions.

According to Stitzer, transposons can regulate and change the expression of nearby genes depending on where they land in the genome. This is important to know, but difficult to identify earlier when their location in the genome sequence was still unknown. Stitzer added that transposon insertions, and their impact on gene expression, are known to impact the way in which the maize plant interacts with its environment. These insertions, for example, confer drought tolerance, altered flowering time, ability to grow in toxic aluminum-rich soils, and have allowed maize to spread to temperate latitudes by breaking sensitivity to the long days of the tropics.

For more, read the UC Davis News.