Month: September 2022

SWITCH FROM RNA TO DNA. "According to the RNA World Hypothesis, life later evolved to use DNA and proteins due to RNA's relative instability and poorer catalytic properties, and gradually, ribozymes became increasingly phased out." https://lnkd.in/eeUzYdR View in LinkedIn

RNA INSTABILITY. "This instability is a necessary precondition for the high productivity of differ- ent RNA sequences with the rapidly adapting features necessary in the early RNA world, that is, a large variety of different RNA identities." Genetic variation engine. https://lnkd.in/euyhznh View in LinkedIn

EARLY CELLULAR REFUGE. "Although accelerated ssRNA processing of mRNA, tRNA and rRNAs in linear RNA genomes built core competences for natural genome editing in the early RNA world, those ssRNAs without cellular habitats are extremely thermolabile and could not survive in high temperature environments." https://lnkd.in/ekWBG2q View in LinkedIn

MEGA-ERRORS ARE INNOVATIVE. "The lack of RNA correction and repair and the high rate of replication combined with innovation allowed a rate of recombination events 1–10 x 10(6) times faster than in DNA genomes." https://lnkd.in/ekWBG2q View in LinkedIn

SUPER-FAST EVOLUTION. "RNA-based life forms could evolve millions of times faster than DNA-based systems. This was an advantage for the exploration and invention of new sequence space, i.e. new genomic content with phenotypic competences and functions." https://lnkd.in/ekWBG2q View in LinkedIn

FASTER ADAPTATION. "In contrast, circular genomes with few higher order regulatory elements (represented by a diversity of genetic parasites present in intron-like genomic habitats) had more advantages in a high temperature environment and could adapt faster because of their ability to exchange selected phenotypes within and between protein-coding data-sets, as happens in horizontal gene transfer." Many bacterial genomes are circular. https://lnkd.in/ekWBG2q View in LinkedIn

FOOTNOTE. "For many years, all bacteria were believed to have a single, circular chromosome in comparison to the eukaryotes, which have linear chromosomes. Perhaps, this was due to the limited sample of bacterial strains studied at the time and the sequencing techniques available to examine the bacterial chromosomes. However, this belief was disproved when bacteria with multiple and/or linear chromosomes were discovered in 1989." https://lnkd.in/eEQunTJ View in LinkedIn

EVOLUTIONARY PATHWAY. "RNA cultures with eukaryote-like RNA-processing seem to predate the evolution of prokaryotes, which adapted to fast-changing environmental conditions by reducing their genomic content to a DNA with nearly analog (intron-free) protein-coding data-sets. This could be the evolutionary pathway from ribozymes of the early RNA world to ribonucleoproteins via low complexity RNA-chaperones to a DNA-protein-based life." https://lnkd.in/ekWBG2q View in LinkedIn

IMMUNITY TO RETROVIRAL INFECTIONS. "As intron-rich linear chromosomes are the preferred habitat for persistent retroviral infections, and because of their important role in host-genetic content (re) arrangements, the invention of bacterial circular genomes must have had an effective immune function against retroviral infections. The result was the evolution of organisms that successfully escaped the high selective pressures of the early RNA world." https://lnkd.in/ekWBG2q View in LinkedIn

MULTIPLE MEANINGS. "During translation from digital DNA storage into the analog code of protein language it is interesting that DNA information contains multiple RNA- and protein meanings, that is, from the same genetic data set it is possible to transcribe multiple RNA species or translate a variety of proteins according to the higher order regulations inherent in epigenetic control and/or transcriptional, pre- or posttranscriptional modification targets." https://lnkd.in/euyhznh View in LinkedIn