Researchers at the University of Arizona and The Institute for Genomic Research have been taking a closer, detailed look at the rice genome and are finding some surprising results.
The rice genome was decoded in 2002, but that effort was essentially a rough draft that relied on automated processes to quickly sequence the DNA of rice. The work on the rice genome at The Institute for Genomic Research is more labor intensive laboratory-bases work. TGIR researcher C. Robin Buell compares the difference between the two as looking at the universe through an off-the-shelf telescope compared to looking at it with the Hubbell Telescope.
The latest look at the rice genome has focused on sequencing the smallest rice chromosome, chromosome 10, and discovered that it had twice as many genes as the initial rough draft indicated. Judith Plesset of the National Science Foundation said in a prepared statement that, “One of the lessons here is, ‘Don’t think you know everything simply because you’ve done the draft.'”
Researchers compared chromosome 10’s proteins to the proteins found in a mustard plant, Arabidopsis, whose genome has been completely sequenced. They found that about two-thirds of the proteins in chromosome 10 were also present in arabidopsis, indicating, according to a press release that,
. . . some of the specific genes responsible for enzyme production, binding of nucleic acids, cell growth and maintenance, cell communication, immunity, development and other functions and processes.
Researchers also found a stretch of heterochromatin on chromosome 10 — a compact string of DNA with few genes whose biological function remains unknown.
Japanese and Chinese research groups have largely finished sequencing chromosomes 1 and 4 respectively, and a full sequence of chromosome 3 is expected by the end of the year.
Source:
Going with the grain: A tale of rice’s smallest chromosome. Press Release, National Science Foundation, June 5, 2003.