Year: 2022

SUPER-PLOIDY. "Most flowering plant lineages have undergone multiple rounds of polyploidy in their ancestry, a process that is ongoing in many lineages. Consequently, supposedly diploid species are in fact palaeopolyploids. For example, the ‘diploid’ A. thaliana may be as high as 48-ploid, and ‘tetraploid’ cytotypes (96-ploid) exist in nature." http://www.sciencedirect.com/science/article/pii/S0959437X15001057 View in LinkedIn

PUZZLING RANGE. "Genome sizes vary more than 2,300-fold among angiosperms, from that of Paris japonica (2n = 12, 1C = ~149 Gbp) to that of carnivorous Genlisea margaretae (2n = ~40, 1C = ~63 Mbp). The biological significance of this massive variation is puzzling." https://lnkd.in/e4xhW7h View in LinkedIn

"GENOME SIZE varies c. 2400-fold in angiosperms (flowering plants), although the range of genome size is skewed towards small genomes. There are two major drivers of this astonishing GS diversity: (i) polyploidy, or whole-genome duplication, causing, at least initially, step-wise increases in GS, and (ii) deviation in repeat copy numbers, that can either result in subtle or more dramatic GS changes." http://www.sciencedirect.com/science/article/pii/S0959437X15001057 View in LinkedIn

TRANSPOSONS KEY. "Transposable elements (TEs) are a dominant feature of most flowering plant genomes...indicate that TEs can explain much about their rapid evolution and diversification. Genome size in angiosperms is highly correlated with TE content and the overwhelming bulk (>80%) of large genomes can be composed of TEs." (Viral fossils). https://lnkd.in/eyHApyP View in LinkedIn

TRANSPOSONS. "In angiosperms the repeat types (i.e. (retro)transposable elements, (micro)satellite DNA, and truncated derivatives) can be fast evolving in absolute copy numbers and sequence, such that in species from many plant families there are reports of repeat element half-lives of 3–4 million years near complete repeat turnover in the genome over timeframes of 5–10 million years, and repeat copy numbers changing GS two or three fold over just a few million years." (GS = genome size). http://www.sciencedirect.com/science/article/pii/S0959437X15001057 View in LinkedIn

MITOCHONDRIAL GENES. "A hallmark of angiosperm mitochondrial DNAs (mtDNAs) is their high rate of recombination and rearrangement, which is reflected in a number of unusual properties. Most angiosperm mtDNAs exhibit extraordinarily high rates of reciprocal, intra- and intermolecular recombination between large direct and inverted repeats, along with less frequent recombination across smaller repeats." https://lnkd.in/e6WHsRJ View in LinkedIn

MITOCHONDRIAL GENE RECOMBINATION. "On an organismal timescale, this leads to genomes consisting of a plethora of subgenomic and multimeric structures whereas on an evolutionary timescale, it results in a highly scrambled gene order between closely related species and sometimes even within a species." http://onlinelibrary.wiley.com/doi/10.1111/nph.13188/full View in LinkedIn

PROMISCUOUS INCORPORATION. "Angiosperm mtDNAs incorporate foreign sequences remarkably often, from chloroplast and nuclear genomes of the same plant via intracellular gene transfer, and from other plants via horizontal gene transfer." http://onlinelibrary.wiley.com/doi/10.1111/nph.13188/full 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

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