RESULTS

The first noticeable result was at first disappointing but turned around later in the trail. At first the rsaL mutation did not have any effect on the production of 30C12-HSL nor on lasl transcription, but it began to appear later in the logarithmic phase of propagation at which time the 30C12-HSL production along with Plasl activity reached homoeostasis in the wild strain while continuing to increase rsaL in the mutant strain of the pathogen. However the sturdy found that:

The increase in rsaL level coincides with the point at which the production of 30C12-HSL diverges in the parent and mutant strains. This is consistent with the conclusion that Rsal induction by 30C12-HSL results in sufficient Rsal to keep 30C12-HSL production at a steady level, balancing the positive feedback action on lasl expression (Rampioni, et. al. 1558)

From this the authors concluded that Rsal is the key molecule that effects the homeostasis of 30C12-HSL production. This could provide the first step in creating the quorum sensing trigger thereby effecting, halting and possibly even reversing the virulent reproduction of the pathogen's population.

The latter part of the previous conclusion is pointed out by the study as well. They believe that further findings suggest that RsaL is a negative autoregulator for the quorum sensing process. Their research has found that the binding of Rsal upon a unique site in the lasl-rsal inergenic region does trigger the divergent transcription on both of the genes sequencing. They refer to this area as Plasl or Prsal dependent on the consideration of the pasl or rsal being considered. There fore their final conclusion of these results is, "that the major funciont of Rsal in P. aeruginossp physiology is to govern the homeostasis of 30C12-HSL by controlling, in concert with Lasl, the expression of...

Besides this Rsal is an integral part of the QS [quorum sensing] signaling network that controls gene expression though different and not mutually exclusive mechanisms… (Rampioni, et. al. 1562)
DISCUSSION

The results of this study seem extremely promising and certainly worth further consideration. They have been cited in numerous other research article on the subject and apperar to be gaining acceptance in the scientific community. The long-range outcome of such forays inot molecular microbiology can certainly be very promising regarding the pathogen Pseudorncnas aeruginos. However even the researcher point out the quorum sensing is a very complex process in any organism and a few chemical transcriptors may not be enough to thoroughly understand and control the process. They believe that is very likely that Rsal does exert a homoestatic effect on the Quorum sensing activity and their results are certainly promising. But even their own results reveal that the difference between the mutated and wild strain showed great variation in results in this experiment and may prove to show even greater results in larger trails of the subject.

While as stated there results are certainly promising, they have opened up the understanding of quorum sensing activity in organism to greater levels and revealed even more complexity than previously thought. This alone is enough to promote much further study into both quorum sensing and the activity of the molecule Rsal on that function.

Works Cited

Rampioni, Giordano, Martin Schuster, Everett Peter Greenberg, Iris Bertani, Marco Grasso, Vittorio Venturi, Elisabetta Zennaro, & Livia Leoni. "RsaL provides quorum sensing homeostasis and functions as a global regulator of gene expression in Pseudomonas aeruginosa." Molecular Microbiology. (2007) 66.6 1557-1565