Plant & Animal Genome IX Conference

Poster: Sequencing & EST
P01_68.html

COLLINEARITY OF SORGHUM AND MAIZE AT THE DNA LEVEL

¹ The Plant Genome Initiative at Rutgers, Waksman Institute Rutgers, The State University of New Jersey Piscataway, NJ 08854-8020. http://pgir.rutgers.edu

² Deptartment of Biological Sciences, Purdue University, West Lafayette, IN 47907

³ Agricultural genomics center, Purdue University, West Lafayette, IN 47907

The genomes of Sorghum (Sorghum bicolor L. Moench) and maize (Zea mays L.), two sister taxa from the grass family, exhibit extensive synteny and sequence conservation at the gene level while being different in size. The 3.5-fold difference in DNA content can be attributed to the tetraploid origin and recent DNA amplification in maize. Comparative analysis of these genomes has exceptional, but largely untested potential not only for the discovery of genes and mobile DNA elements but also for the determination of gene distribution and the nature, rates, and mechanisms of evolutionary change in Poaceae. We have used Bacterial Artificial Chromosome (BAC) clones ranging in size from 100 to 160 kb to isolate orthologous regions from sorghum and maize containing the following maize loci: 1)r1/b1, 2)tbp1/tbp2, 3)orp1/orp2, 4)c1/pl1, 5)rp1 and 6)tb1. Here, we will present data on the collinearity in the region surrounding the r1 and b1 loci in maize and sorghum. The dissection of microcollinearity between these two closely related species that differ greatly in genome size support the idea that small genomes can be used as surrogate for map-based cloning of genes in large genomes.