Marc A. Marti-Renom, PhD, a computational biologist who leads the Structural Genomics Laboratory at the Prince Felipe Research Center in Spain, and study author said "This work demonstrates that hybrid methods combining 5C maps with the Integrative Modeling Platform can produce genome-wide 3D models of unprecedented resolution, which for the first time allows for spatially pinpointing regulatory elements responsible of organizing the structure of a genome."
The resulting 3D models of the Caulobacter crescentus genome, in conjunction with fluorescent microscopy, illustrate that the parS sequence, located in the pole of one arm of the chromosome, potentially served as an anchor for the genome and were instrumental in defining its overall structure.
To unravel the role the parS site plays in the 3D organization of the chromosomal structure, Dekker and colleagues constructed mutant bacteria in which the parS site had been moved away from its normal position. Building 3D models of the shape of the mutated bacteria, they observed a change in the chromosome's structure; the entire genome had rotated clockwise.
Changing the position of the parS site had resulted in a large-scale reorganization of the chromosome's shape that repositioned these sites at the cell's poles. Mark Umbarger, a post doctoral fellow at Harvard Medical School and study author notes, "Strikingly, we found that moving sequence elements which are no larger than 500 base pairs, led to a change in the conformation of all of the 4 million base-pairs of the chromosome!"
"Our study is the first to test the effect of altering chromosome architecture. We were able to show that a very simple system, with a single anchor, can orient the whole chromos
|Contact: Jim Fessenden|
University of Massachusetts Medical School