• rates
  • There is a systematic difference in mutation rates for transitions (Alpha) and transversions (Beta). (wikipedia.org)
  • Other cases in which symbiont microevolution has a major effect on host ecological tolerance are likely to be widespread because of the high mutation rates of symbiotic bacteria and their crucial roles in host metabolism and development. (pubmedcentralcanada.ca)
  • response
  • Recently, there have been studies suggesting that these mutations occur in response to environmental challenges. (wikipedia.org)
  • This Buchnera mutation virtually eliminates the transcriptional response of ibpA to heat stress and lowers its expression even at cool or moderate temperatures. (pubmedcentralcanada.ca)
  • This mutation arose and was fixed twice in sublines derived from a single female aphid in the lab and kept at constant 20 °C. Experiments using aphid lines that differed only in the presence of this Buchnera mutation revealed that it eliminates the ibpA transcriptional response to heat shock and affects ibpA expression at low temperatures. (pubmedcentralcanada.ca)
  • cells
  • When cells were deprived of a certain amino acid, tryptophan, for prolonged periods of time, point mutations in trp operon reverted to tryptophan, leading to an advantageous result, more frequently than under normal conditions when the mutations were neutral. (wikipedia.org)
  • In addition, the tryptophan mutation rate was unaffected when the cells were deprived of another amino acid, cysteine, further suggesting that the mutation rate was specific to situations in which the mutation was advantageous. (wikipedia.org)
  • MSA prions robustly infected wild-type, A30P, and A53T α-synuclein-YFP cells, but they were unable to replicate in cells expressing the E46K mutation. (pnas.org)