sRNA for Quorum Sensing: Evidence for CSI?
|November 9, 2013||Posted by DLH under Evolution, Intelligent Design, Darwinism, Irreducible Complexity, Origin Of Life, Genomics, speciation, Evolutionary biology, Genetics, Cell biology, Complex Specified Information, Symbiosis|
Bacteria demonstrate intra-species communication that is species specific using a partner with a communication molecule. Bacteria are also “multilingual” with a generic trade language for interspecies communication. Bacteria control tasks by signal producing and receiving receptors with a signal carrier. The tasks bacteria conduct depend on the concentration they sense of self bacteria versus generic species concentration. e.g. Bacteria control pathogenicity with quorum sensing. The detailed (small) sRNA required for these control mechanisms is now beginning to be desciphered. See below. Question:
Did bacteria “invent” their communication and control methods via evolutionary stochastic processes?
Or do these constitute Complex Specified Information and thus evidence design?
Functional determinants of the quorum-sensing non-coding RNAs and their roles in target regulation.
EMBO J. 2013 July 31; 32(15): 2158–2171. Published online 2013 July 9. doi: 10.1038/emboj.2013.155 PMCID: PMC3730234
Quorum sensing is a chemical communication process that bacteria use to control collective behaviours including bioluminescence, biofilm formation, and virulence factor production. In Vibrio harveyi, five homologous small RNAs (sRNAs) called Qrr1–5, control quorum-sensing transitions. Here, we identify 16 new targets of the Qrr sRNAs. Mutagenesis reveals that particular sequence differences among the Qrr sRNAs determine their target specificities. Modelling coupled with biochemical and genetic analyses show that all five of the Qrr sRNAs possess four stem-loops: the first stem-loop is crucial for base pairing with a subset of targets. This stem-loop also protects the Qrr sRNAs from RNase E-mediated degradation. The second stem-loop contains conserved sequences required for base pairing with the majority of the target mRNAs. The third stem-loop plays an accessory role in base pairing and stability. The fourth stem-loop functions as a rho-independent terminator. In the quorum-sensing regulon, Qrr sRNAs-controlled genes are the most rapid to respond to quorum-sensing autoinducers. The Qrr sRNAs are conserved throughout vibrios, thus insights from this work could apply generally to Vibrio quorum sensing.
(Emphasis added vis CSI). Researchers are now working to make disease specific communicators which have potential for next generation antibiotics. It is now possible to modulate quorum sensing. e.g. see:
A quorum-sensing inhibitor blocks Pseudomonas aeruginosa virulence and biofilm formation
For a popular discussion see the TED presentation: How bacteria talk
Bonnie Bassler discovered that bacteria “talk” to each other, using a chemical language that lets them coordinate defence and mount attacks. The find has stunning implications for medicine, industry – and our understanding of ourselves.
Bonnie Bassler studies how bacteria can communicate with one another, through chemical signals, to act as a unit. Her work could pave the way for new, more potent medicine. In 2002, bearing her microscope on a microbe that lives in the gut of fish, Bonnie Bassler isolated an elusive molecule called AI-2, and uncovered the mechanism behind mysterious behavior called quorum sensing — or bacterial communication. She showed that bacterial chatter is hardly exceptional or anomolous behavior, as was once thought — and in fact, most bacteria do it, and most do it all the time. (She calls the signaling molecules “bacterial Esperanto.”)
See other publications on Quorum Sensing
See previous UD posts on quorum sensing: “Bacteria: They don’t think, but something in them thinks”
“Another Layer on the Information Story: Quorum Sensing”
Update: See further discussion at the following post: Traces of life forms found from 3.5 billion years ago