K/Kis directly correlated with codon bias, here measured using the ENC' statistic (49; lower ENC' prime values indicate higher codon bias) in () , () , and ()

<p><b>Copyright information:</b></p><p>Taken from "Positive selection for unpreferred codon usage in eukaryotic genomes"</p><p>http://www.biomedcentral.com/1471-2148/7/119</p><p>BMC Evolutionary Biology 2007;7():119-119.</p><p>Published online 18 Jul 2007</p><p>PMCID:PMC1936986.</p><p></p> Error bars indicate standard error. This relationship suggests that recent selective pressures on codon usage in these groups generally reinforce historic selective pressures

Frequencies of different forms of splice variation, arranged by phylogenetic group

The two bar charts show the relative frequencies of each type of splice variation. The ratio of CEs to RIs is shown in the chart on the left, while the one on the right displays competing 5' and competing 3' splice sites. Note that the CE/RI ratio shows wide variation among kingdoms while the ratio of competing 5' to competing 3' splice sites is remarkably consistent. A high-level overview of the phylogenetic tree is shown on the far left, and the organisms' names are colored according to their phylogenetic grouping. To see all four forms of splice variation on a single bar plot, see Additional data file 1. The data for was taken from a previous study [8].<p><b>Copyright information:</b></p><p>Taken from "Cross-kingdom patterns of alternative splicing and splice recognition"</p><p>http://genomebiology.com/2008/9/3/R50</p><p>Genome Biology 2008;9(3):R50-R50.</p><p>Published online 5 Mar 2008</p><p>PMCID:PMC2397502.</p><p></p

Average lengths of RIs compared with lengths of constitutive introns and introns adjacent to CEs

RI length, which is constrained by ID, is fairly constant across all organisms. In protists and fungi, average RI length is close to that of constitutive introns, because ID is the primary mode of splice site recognition for both groups. In animals, constitutive intron length differs substantially from RI length because most constitutive introns are recognized by ED and are not subject to the same length constraints as RIs, which are recognized by ID. Plants fall between unicellular organisms and animals. Data are shown only for organisms with at least five RIs. For introns next to CEs, data are shown only for organisms with at least eight CEs with unambiguous adjacent intron lengths on both sides. Introns next to CEs are usually longer than constitutive introns, because these introns are recognized by ED and are free from ID length constraints.<p><b>Copyright information:</b></p><p>Taken from "Cross-kingdom patterns of alternative splicing and splice recognition"</p><p>http://genomebiology.com/2008/9/3/R50</p><p>Genome Biology 2008;9(3):R50-R50.</p><p>Published online 5 Mar 2008</p><p>PMCID:PMC2397502.</p><p></p

Average lengths of CEs compared to average lengths of internal constitutive exons

Species are sorted by the fractional difference between these two lengths. In organisms where CEs are common (animals and plants) CEs are almost identical in length to constitutive exons, while in species where CEs are rare (fungi and protists) CEs tend to be significantly shorter than constitutive exons. In animals and plants, where ED is common, CEs are spliced by the same process as constitutive exons and these two groups are thus subject to the same length constraints. In organisms that splice primarily by ID, including fungi and protists, the lengths of constitutive exons are not constrained by ED. However, CEs in these organisms are still recognized by ED. Thus, in these species, constitutive exons can grow longer than CEs.<p><b>Copyright information:</b></p><p>Taken from "Cross-kingdom patterns of alternative splicing and splice recognition"</p><p>http://genomebiology.com/2008/9/3/R50</p><p>Genome Biology 2008;9(3):R50-R50.</p><p>Published online 5 Mar 2008</p><p>PMCID:PMC2397502.</p><p></p