Rose may be a rose in some books, but in actuality flowers are deeply divided - that is, between eudicots and monocots, the two major classifications of flowering plants. However, despite the 130-240 million years of evolution separating monocots and dicots, scientists have predicted that the relative order of their genes will be fairly similar, as it is for mice and men (70 million years separation). In the September issue of Genome Research, Katrien Devos (John Innes Centre), Takuji Sasaki (Rice Genome Research Program), and colleagues take aim at this notion by showing that gene order in Arabidopsis, a model eudicot of the mustard family, is not preserved in rice, a model monocot.
Long a favorite among researchers, Arabidopsis is in fact the only plant for which most of the genetic sequence is known. Devos and colleagues compared the gene order of Arabidopsis and rice by selecting genes from a limited region of Arabidopsis chromosome 1 and searching for their counterparts in the known rice sequence. They found that the rice genes they located in this manner were scattered over 10 of the 12 rice chromosomes, indicating that gene order is not preserved between Arabidopsis and rice. These results not only reveal an evolutionary divide between dicots and monocots but also caution scientists hoping to exploit Arabidopsis sequence for understanding cereal crops like rice and wheat. When it comes to gene sequence, there may be no substitute for the real thing.
Contact information:
Katrien Devos
John Innes Centre
Norwich Research Park
Colney, Norwich NR4 7UH
United Kingdom
Fax: 44-1603-502-241
Email: katrien.devos@bbsrc.ac.uk
Journal
Genome Research