The researchers also used the sorghum genome as a comparative reference. Their analysis indicated thatM. sinensis arose as a result of a duplication of the sorghum genome, with a later fusion of some chromosome parts.
"Some plants will duplicate their genomes and then there's some sorting that goes on," Moose said. "Sometimes whole chromosomes are lost and sometimes there are fusions." Once there are two copies of each chromosome in a base set, each will proceed along its own evolutionary trajectory. "Often what will happen is even though there are two (versions of the same chromosome), one of them will start to deteriorate over time," Moose said. "Some positions and some genes will win out over the others."
Genome duplications may undermine the viability of a plant or give it an advantage. One immediate advantage of doubling, tripling or otherwise duplicating the genome is that it increases the size of the plant, or of certain plant parts, Moose said.
"Humans have selected for these traits," he said. "Strawberries, for example, are octoploids; they have eight chromosome sets. Sugarcane has eight sets, and it's bigger (than its wild cousins)."
Moose and his colleagues were surprised to find a high degree of similarity between the Miscanthus and sorghum genomes.
"I would say that for about 90 percent of the Miscanthus markers, their chromosomal order corresponds to what is known for sorghum," he said.
The new findings and the eventual publication of the Miscanthus genome will help scientists understand the
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign