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SIZE IMPEDIMENT. "Plants with large genomes may have low speciation rates, are not well adapted to extreme environments, and have low maximum photosynthetic rates." https://lnkd.in/bCmw3Fr View in LinkedIn

SUPPRESSION OF TRANSPOSABLE ELEMENTS. "Almost all species contain mechanisms to silence TEs. TE insertion precedes the smRNA mechanisms that silence TEs." (TE = transposable element). https://lnkd.in/bCmw3Fr View in LinkedIn

SIZE THRESHOLDS MATTER. "Maximum genome size and monoploid number thresholds also affect the relationship between average genome size and ploidy level. The evidence for the importance of genome size threshold mainly comes from the simulations of tetraploids, for which genome sizes thresholds best explained the mean genome size in both the genus and species simulations." https://lnkd.in/bCmw3Fr View in LinkedIn

TRANSPOSON DRIVER. "Because 24-nt smRNAs are amplified from transposons and because smRNA coverage, presumably to transposons, tags the gene on the recessive subgenome even when that gene is, unexpectedly, expressed more than its homeolog, perhaps transposon coverage is the real driver of genome dominance." https://lnkd.in/bCmw3Fr View in LinkedIn

SIZE MAY NOT MATTER. "Our genome downsizing simulations indicate optimal genome downsizing rates between 0 and 30% across polyploidy series taxa, species, and genus analyses. Genome downsizing does not necessarily have to be large to explain the lack of a strong relationship between average genome size and ploidy level, and at the genus level, it may not play a role at all." https://lnkd.in/bCmw3Fr View in LinkedIn

STARRING ROLES. "What is the mechanism used by plants (or eukaryotes) to change quantitative balances of gene expression rapidly? Not surprisingly, relatively rapid changes in transposon content play the starring roles in our genome dominance mechanism." https://lnkd.in/bCmw3Fr View in LinkedIn

SO ENDS our venture into the evolution of flowering plants, their rapid emergence, domination of plant life, and their remarkable phenotypic adaptations and co-evolution with pollinators. Driving this success story has been the common whole genome duplication, which occurred more than once and independently. The detailed story about gene duplication is another topic for another time. View in LinkedIn

TRANSPOSON CONTROL. "There is a fitness tradeoff between keeping transposons controlled and the mRNA level of adjacent genes; small genomes like A. thaliana, those more efficient at transposon silencing, maintain relatively low levels of mRNA in comparison to the larger, more highly expressed A. lyrata." https://lnkd.in/bCmw3Fr View in LinkedIn

GENOME CONTRACTION. "Twenty-four ancient plant polyploidies have been documented within plant genomes as of January 2014. In maize, some crucifers, and perhaps all new plant polyploids, fractionation (loss of duplicated genes) and diploidization (return to diploid meiotic behavior) happen within a few million years of the WGD. In the grasses, both fractionation and diploidization are relatively rapid." (WGD = whole genome duplication). https://lnkd.in/bCmw3Fr View in LinkedIn

TRANSPOSON EFFECTS. "We hypothesize that following a chaotic wide-cross/new tetraploid period, genes acquire their new expression balances based on differences in transposon coverage in the parents. We envision patches of silenceable transposon as quantitative cis-regulators of baseline transcription rate." https://lnkd.in/bCmw3Fr View in LinkedIn