UC San Diego

First discovered in maize by Barbara McClintock, mobile elements inserted in the control regions or coding regions can alter gene activity. Under stress condition, transposons inserted into specific chromosomal sites provide the host with various benefits. The activation of downstream genes can be caused by creating a novel promoter, a hybrid promoter, disruption of repressor binding site, or activation of a native promoter via a transposon. Insertion Sequence 5 was previously found to activate glpFK operon expression (Zhang, et al. 2009) by replacing Crp and directly activating the native downstream promoter. When IS5 is inserted upstream of PflhDC in various locations and orientations, the mutant increase their motility. This study was conducted with the intension of determining the degree of activation of PflhDC and its effector genes, as well as of uncovering the gene activation mechanism for hyper swarming