Nature takes this genetic conservation to some unexpected extremes. The eyes of the octopus and humans are created from different tissues when the body is an embryo, yet scientists have discovered the eyes in both creatures are coded by the same genes.
"Twenty years ago, if you had told a biologist that the eyes of a human and an octopus arise from the action of the same gene, he would have thought you were being ridiculous," Bennetzen says.
Woodson says these slight differences in gene structure and gene function determine the amazing diversity in organisms. "The science of genomics will begin to unravel this mystery, opening up untold opportunities for the application of genetic technology to crop and livestock production, as well as to human health."
Making Maps Of Plants
Genetic conservation goes beyond just having certain genes in common. Plant scientists have discovered in the past few years that if they determine the location of a gene for a specific trait in one plant, another plant in the same family is likely to have the gene in the same place.
This is a boon to plant breeders. Today, the fastest way to improve corn might be to study the genetics of sorghum. Corn's genome is three times larger than sorghum. By identifying genes for a desired trait, such as drought tolerance, in sorghum, researchers know where to look for it in corn.
For example, Purdue horticulture professors Ray Bressan and Michael Hasegawa will use the techniques of genomics to locate genes that help plants withstand stresses such as drought, heat, cold and poor nutrition.
"They're using an approach called EST, or Expressed Sequence Tags," Woodson says. "They take
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Contact: Steve Tally
tally@aes.purdue.edu
765-494-9809
Purdue University
11-Feb-2001