Given that the trends we observed here are general for all detectable duplicates, future studies will be needed to address the possible differences between duplicates of different origin.
For the paralogs participating in different complexes (bi-complex paralogs), we see a quantitative difference between duplicates of different age, with only a minority of bi-complex paralogs stemming from WGD.
Among recent duplicates of different modes, transposed duplicates diverge most dramatically in gene structure.
Experiments were performed in biological triplicates and with duplicates of different concentrations of the extracted proteins.
Various duplicates of different GS gene families code for proteins encoding functions in consecutive steps of GS biosynthesis (Kliebenstein et al. 2001; Hansen et al. 2007).
Thanks to a low rate of large scale genome rearrangement in Paramecium, an unprecedented large number of gene duplicates of different ages have been identified, making this organism an outstanding model to investigate the evolutionary consequences of polyploidization.
Uneven retention of gene duplicates on different chromosomes resulting from a quadruplication has been observed previously for the paralogon comprised by the human chromosomes 4, 5, 8 and 10 [ 82] as well as for chromosomes 1, 6, 9 and 19 [ 83].
According to Hughes [23], "specialization" of duplicates to different functions of the bi-functional ancestral gene can occur through positive selection.
This organism experienced a recent whole-genome duplication event [ 13] that, together with smaller segment duplications provided material for comparison of duplicated genes of different origin.
Arabidopsis duplicated genes of different modes are listed in Additional file 1.
Analysis of the age distribution of gene duplications supported a continuous mode of small-scale duplications, plus two episodes of large-scale duplicates of vastly different ages.
