00:01
Hello everyone, in this question we have been said to describe how the evolutionary process begin might account for the origin and persistence of cell to cell signaling systems in unicellular prokaryotes.
00:18
So basically, cell signaling is the part of any communication process that governs the basic activities of cell and helps to coordinate the multiple cell reaction.
00:30
Like we can see cell development, tissue repair, immunity, homeostasis, etc.
00:38
Can be seen due to the result of the cell signaling.
00:43
So here let us say this is the cells.
00:46
On the cell surface there is receptor to which the ligand will bind and due to which this receptor will activate the other proteins and so at the end we will see the response.
01:00
So in this first of all the signal perception is there and then intracellular signal transduction takes place and then the cellular response takes place.
01:09
So there is a considerable amount of similarity between the cell signaling mechanism of yeast and humans.
01:19
So the evolutionary processes and the origin of and persistence of cell signaling is there like we can see in forum signaling.
01:28
So the majority of forum sensing systems that fall under the two gene, the autoinducer synthase coupled with the receptor molecule and this here is defined by the vibrio fischeri system that occurred in the gram negative proteobacteria.
01:51
So a comparison between the proteobacteria phylogeny as generated by the 16s ribosomal rna sequence and phylogenesis of the lux i, lux r or lux s homologues show notably high level of the global similarity.
02:12
So due to this lux i only the autoinducers are produced due to which the quorum signaling takes place.
02:22
So overall the quorum sensing genes seem to have diverged along the proteobacteria phylum as a whole and this indicates that the quorum sensing system are quite ancient and arose very early in the proteobacteria lineage.
02:38
Although examples of horizontal gene transfer are apparent in the lux i, lux r and lux s phylogenies, they are relatively rare and this result is in the line with the observation that quorum sensing genes tend to control the expression of a wide area of genes scattered throughout the bacterial chromosome.
03:03
In the quorum sensing of gamma proteobacteria which includes the pseudomonas aeruginosa and e.
03:11
Coli, the lux i and lux r genes from a functional protein form a functional pair with lux i as the autoinducer synthase and lux r as the receptor...
