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BLOOM AND PURGE. "We hypothesize that when two genomes come together in an allotetraploid, one genome has invariably made compromises to a different level than the other based on differences in transposon bloom-and-purge history and the degree of selection against TE amplification." (TE = transposable element). https://lnkd.in/bCmw3Fr View in LinkedIn

REVERSIBLE POLYPLOIDY. "Thus, it is immediately apparent that polyploidy is, at least in part, reversible, and that over time it is followed by massive chromosomal rearrangements, reductions in chromosome number, and the large-scale loss of both repetitive sequences and duplicated genes all leading to genome downsizing." http://www.amjbot.org/content/early/2015/10/09/ajb.1500320 View in LinkedIn

POSITION EFFECT. "Hollister et al., provided strong evidence that TE silencing represents a tradeoff between the primary selection to reduce transposon expression and the consequent reduction in levels of gene expression for genes near transposons via a position effect whereby the silencing of the transposon spreads to an adjacent gene’s promoter." (TE = transposable element). https://lnkd.in/bCmw3Fr View in LinkedIn

THEORY VS PRACTICE 2. "Similarly, and notwithstanding the uncertainty regarding actual ancestral angiosperm genome sizes, if one postulates a small ancestral genome size of, say, 300 megabases, in the absence of countervailing forces the modern G. hirsutum genome should be enormous, 43.2 gigabases (Gb), instead of the 2.4 Gb that it actually contains." http://www.amjbot.org/content/early/2015/10/09/ajb.1500320 View in LinkedIn

TRANSPOSABLE ELEMENT (TE) LOAD. "Because the two subgenomes of an allotetraploid originate from two different genomes existing tens of millions of years ago, each with what must have been different transposon populations, bloom histories, distributions, and levels, we hypothesize that a differential load of TEs in the parental lines is a sufficient explanation for the origin of subgenome dominance." https://lnkd.in/bCmw3Fr View in LinkedIn

THEORY VS PRACTICE 1. "If one assumes that the ancestral angiosperm chromosome number is 5–7, as often suggested, then modern Gossypium hirsutum, for example, should have 5–7 times 144, or 720–1008 chromosomes in its haploid complement, in the absence of massive, repeated chromosome number reduction, instead of the 26 it actually contains." http://www.amjbot.org/content/early/2015/10/09/ajb.1500320 View in LinkedIn

CONSEQUENCES. "Some of the longer-term consequences of repeated, cyclical polyploidy become evident when one considers that lineages having experienced multiple historical rounds of polyploidy do not exhibit especially high chromosome numbers nor genome sizes." http://www.amjbot.org/content/early/2015/10/09/ajb.1500320 View in LinkedIn

CASCADE OF TRAITS. "Even more varied yet poorly understood is the gamut of short-term evolutionary responses to polyploidy at other “omics” levels, including a diverse suite of epigenomic and small RNA alterations with cascading effects that propagate through proteomic, physiological, and metabolomic networks to ultimately affect plant phenotype and function." http://www.amjbot.org/content/early/2015/10/09/ajb.1500320 View in LinkedIn

UNNATURAL AND DISORDERLY. "The invention of artificial parthenogenesis represented an attack on the privileged status of natural modes of reproduction. A race of fatherless sea urchins was a nonnatural product completely outside the orderly structure and gradual evolution of the animal economy." https://lnkd.in/eQf5Evv View in LinkedIn

NO BIOLOGICAL SIGNIFICANCE. "Such an objection could not so easily be made against artificial parthenogenesis. It was a change in the mode of production (or reproduction), an improvement upon nature in that it eliminated an unnecessary element (the sperm), and offered the possibility of replacing half the sea urchin population with a mixture of salts." https://lnkd.in/eQf5Evv View in LinkedIn