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SUMMARY:Prof. Anthony Poole\, University of Auckland (NZ): Experimental ev
 olution sheds insights on the intracellular lifestyle
DTSTART;TZID=Europe/Berlin:20241119T090000
DTEND;TZID=Europe/Berlin:20241119T100000
DTSTAMP:20260407T164348Z
UID:0d7910b2b5274356b175ed0dfb2448e5@www.uni-marburg.de
CREATED:20240913T110822Z
DESCRIPTION:https://www.uni-marburg.de/en/synmikro/grk2937/whats-on/dates-
 and-events/prof-anthony-poole-university-of-auckland-nz\nSpeaker Series. A
 bstract: Intracellularity leads to some quite unusual changes to genomes a
 nd to nucleotide metabolism. I will present the results of two studies tha
 t make use of experimental evolution for to examine the evolution of two p
 henomena. In the first project\, I will present work from our lab on the i
 mpact of knocking out genes for ribonucleotide reduction in the bacterium 
 E. coli. We document the dependence of these bacteria on externally-suppli
 ed deoxyribonucleosides\, mimicking the loss of this process in some intra
 cellular bacterial species\, including Ureaplasma\, Borrelia and Buchnera.
  Our experiment revealed subsequent gene losses that were also found to ha
 ve naturally occurred in these species. The paradox we observed was that t
 he gene losses that emerged following loss of ribonucleotide reduction pre
 vented the potential for evolution to make use of an alternative mechanism
  for dNTP synthesis\, suggesting that a short term benefit trumps the long
  term potential in this system. The second project involves the serial bot
 tlenecking of E. coli to see whether genetic drift hastens the emergence o
 f genomic errors that can be corrected via slippage (during) or via editin
 g (after) transcription. Such processes are quite common in intracellular 
 bacteria such as Buchnera\, but also are found in eukaryotic organelles of
  bacterial origin. Our results show that\, under conditions favouring gene
 tic drift\, we do indeed observe an increased probability of the evolution
  of these processes. We conclude that our experiments support the idea of 
 constructive neutral evolution\, a process by which genetic drift leads to
  more complex molecular processes with no immediate advantage. In both cas
 es\, the ancestral state did not require the capacity for slippage or edit
 ing\, but\, at the end of the experiment\, loss of such processes would un
 mask sublethal mutations - the genomes must now be corrected during gene e
 xpression to avoid this.
LAST-MODIFIED:20241018T094638Z
LOCATION:SYNMIKRO Lecture Hall
URL:https://www.uni-marburg.de/en/synmikro/grk2937/whats-on/dates-and-even
 ts/prof-anthony-poole-university-of-auckland-nz
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