In an effort to streamline the way that researchers identify and sequence the DNA in those gene-rich islands, scientists at The Institute for Genomic Research and collaborators have discovered that two different approaches to identifying the non-repetitive regions of the genome together provide a complementary and cost-effective alternative to sequencing the entire genomes of complex plants.
In a paper published in the December 19th issue of the journal Science, the researchers found that two independent gene-enrichment techniques methylation filtering and High-C0t selection target somewhat distinct but overlapping regions of the genome and therefore could be used together to help identify nearly all of the genes in maize as well as their genomic structures.
This finding is significant because the maize genome, which includes about 2.5 billion base pairs of DNA, is about 20 times larger than the first plant genome to be deciphered, Arabidopsis thaliana, and nearly six times larger than the rice genome. The reason that the maize genome is so large is that approximately 80% consists of families of nearly identical repetitive sequences. The gene-containing sequences are concentrated in the remaining 20% of the genome.
The challenge for genomic researchers is to explore the gene-rich islands without having to negotiate through the sea of highly-repetitive DNA surrounding them. In the Science study, researchers reported on two "filtration" techniques that separate the gene-rich regions from the gene-poor ones, providing about a four-fold reduction in the amount of sequencing ne
Contact: Robert Koenig
The Institute for Genomic Research