Month: September 2022

“TRANSPOSASES hold a special place in the pantheon of genome sculptors. Arguably the products of the most abundant genes on Earth, transposases are transposon-encoded enzymes that cleave transposon ends and attach them to new sequences.” http://science.sciencemag.org/content/338/6108/758 View in LinkedIn

IMPACT OF STRESS. “Evidence is accumulating that both biotic and abiotic stresses induce a heritable increase in the ability of plants to withstand infection and tolerate stress. DNA damage, pathogen infection, and abiotic stresses also increase homologous recombination frequency and chromosomal rearrangements, both somatically and heritably.” http://science.sciencemag.org/content/338/6108/758 View in LinkedIn

INVITATION TO JUMPING GENES. “Thus, responses to stress—whether from pathogens, environmental extremes, or damage to the genetic apparatus—evoke not just a transcriptional response, but also a profound and to some extent heritable change in the epigenetic framework. Such changes can loosen the epigenetic constraints on transposons, allowing stress-inducible TEs to propagate stress-inducible promoters to other genes through transposition.” http://science.sciencemag.org/content/338/6108/758 View in LinkedIn

DRIVEN BY JUMPING GENES. “It is becoming increasingly difficult to escape the conclusion that eukaryotic genome evolution is driven from within not just by the gentle breeze of the genetic mechanisms that replicate and repair DNA, but by the stronger winds (with perhaps occasional gale-force gusts) of transposon activity. The ability to evoke rapid genome restructuring is at the heart of eukaryotic evolvability—the capacity of organisms with larger and larger genomes to maintain evolutionary flexibility.” http://science.sciencemag.org/content/338/6108/758 View in LinkedIn

SO ENDS this second and last weekend on jumping genes. These often autonomous mobile threads of DNA have been important architects of genetic variation across species, liberally sharing genes and making new genes. Like prions, which are just clumps of tangled protein, these chemical threads can proliferate, infect, and move around in the cellular or genomic (respectively) ecosystems that they inhabit. They push our understanding of the boundaries of what it is to be alive towards information that can replicate itself and evolve. View in LinkedIn

“DUPLICATION is not the same as life. Complex chemicals are capable of duplication. Amino acids and protein are not alive, but they duplicate and are a requirement for replication. Proto-life catalyzes and carries information required for its own existence.” https://lnkd.in/dSqra5e View in LinkedIn

COMPELLED COMPLEXITY. “We show that, because natural selection forces genomes to behave as a natural “Maxwell Demon,” within a fixed environment, genomic complexity is forced to increase.” http://www.pnas.org/content/97/9/4463.full View in LinkedIn

INFORMATION IS PHYSICAL. “A key aspect of information theory is that information cannot exist in a vacuum; that is, information is physical. This statement implies that information must have an instantiation (be it ink on paper, bits in a computer's memory, or even the neurons in a brain). Furthermore, it also implies that information must be about something. Lines on a piece of paper, for example, are not inherently information until it is discovered that they correspond to something, such as (in the case of a map) to the relative location of local streets and buildings.” http://www.pnas.org/content/97/9/4463.full View in LinkedIn

SHARED SCRIPT. “An organism's DNA thus is not only a “book” about the organism, but is also a book about the environment it lives in, including the species it co-evolves with. It is well known that not all of the symbols in an organism's DNA correspond to something. These sections, sometimes referred to as “junk-DNA,” usually consist of portions of the code that are unexpressed or untranslated (i.e., excised from the mRNA).” http://www.pnas.org/content/97/9/4463.full View in LinkedIn

THE KEY. “Non-coding RNA holds the key to development and evolution of complexity.” https://lnkd.in/dMrxDE5 View in LinkedIn