Category: Uncategorized

OXIDATIVE DAMAGE THEORY. "Did Meiotic Sex Evolve in Response to Reactive Oxygen Species? Lately, more and more research has uncovered links between stress conditions, such as Reactive Oxygen Species formation, and meiotic sex. One essential question of course remains: where did the Reactive Oxygen Species that possibly gave rise to the invention of meiotic sex in eukaryotes come from?" https://lnkd.in/deZ8DED View in LinkedIn

OXIDATIVE DAMAGE THEORY. "Did Meiotic Sex Evolve in Response to Reactive Oxygen Species? Lately, more and more research has uncovered links between stress conditions, such as Reactive Oxygen Species formation, and meiotic sex. One essential question of course remains: where did the Reactive Oxygen Species that possibly gave rise to the invention of meiotic sex in eukaryotes come from?" https://lnkd.in/deZ8DED View in LinkedIn

LESSONS LARNED. "The bdelloid rotifers have more to tell us. Genomic analysis shows gene conversion, limiting the accumulation of mutations in absence of meiosis. Genes defending against transposons are increased, correlating with the fact that transposable elements make up only 3% of the genome. Horizontal gene transfer is very abundant, with 8% of the genes most likely acquired in this fashion. In this respect, bdelloids seem to have “returned” to the prokaryotic form of sex." https://lnkd.in/deZ8DED View in LinkedIn

TWO WORLDS. "Thus, despite the presence of organisms with long periods of clonality and occasional instances of aneuploidy and parasexuality, which deviate from regular standard meiotic sex, its option is still overwhelmingly present in practically all eukaryotes." https://lnkd.in/deZ8DED View in LinkedIn

CLONAL UNDER STEADY STATE. "Under more constant optimal conditions, relatively simple organisms with short generation times are selected for high numbers of progeny, which can most efficiently be achieved by asexual reproduction. Thus, clonal reproduction may last for an extended period. However, when adverse conditions or internal constraints are encountered, sex is induced." https://lnkd.in/deZ8DED View in LinkedIn

FITNESS BENEFIT. “Another potential benefit of cell–cell fusion is hybrid fitness: If, as seems likely, there existed a variety of fledgling protoeukaryotes in the population that eventually gave rise to the last eukaryotic common ancestor, then their fusion would be expected to have yielded more gene-rich and occasionally more successful lineages.” http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

UTILITY OF REDUNDANCY. “Increases in ploidy confer indubitable benefits: The resultant redundancy allows novel sequences/functions to arise in duplicate genes without compromising existing pathways, and recessive nonadaptive alleles, masked but carried through time, may prove to be adaptive in future contexts.” https://lnkd.in/ebVhXPf View in LinkedIn

ENGULFMENT. “An alternative possibility, leading to the same outcome, is that the earliest versions of cell–cell fusion entailed the engulfment of one protoeukaryote by another, with the internalized cell membrane then either digested or fused with the host cell membrane from within.” http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

PROVENANCE. “That Spo11 was present in the last eukaryotic common ancestor can be inferred by its presence in all of the major eukaryotic lineages studied thus far, with the notable exception of Dictyostelium discoidium and closely related slime molds that have apparently lost Spo11 but undergo complete meiotic sexual cycles.” https://lnkd.in/ebVhXPf View in LinkedIn

GENOME EXPANSION. “Cell–cell fusion generates an increase in chromosome number, and although the large size of modern eukaryotic genomes could also have been the consequence of endomitosis, it seems likely that cell–cell fusions contributed to genome expansion during protoeukaryote evolution.” http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn