Year: 2022

TRADEOFFS. "We propose that successful ancient tetraploids begin as wide crosses between two lines, each evolved for different tradeoffs between transposon silencing and negative position effects on gene expression." 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

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 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

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

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

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

Goodbye, Earth: 'We're going to live on Mars in 2027' 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

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