Table 6. The asymmetric divergence of split autosomal-X paralog pairs: the loss of transcription factor binding sites, a shift towards capped expression (i.e., limited in the maximal level) and a shift towards more tissue-specific expression on the X.
| The timing of the duplication event (estimated by phylogenetic timing). | The number of duplication events (i.e., unique nodes in TreeFam phylogenetic trees which are classified as duplications rather than speciation events). | ΔBoE | ΔTfbsNo | ΔMAXIMAL | Expression in selected tissues | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| RR | Not-R | Auto→X | X→auto | Total | B | M | F | ||||
| Human | 0 | 0 | 0 | 0 | 0 | NA | NA | NA | |||
| Human/Chimpanzee/Gorilla | 0 | 2 | 1 | 2 | 5 | 0.44 | 4 | 45±104 | 1 | 1 | 1 |
| Catarrhini | 0 | 3 | 4 | 0 | 7 | -0.43 | -6.28 | -93±113 | 7 | 1 | 1 |
| Eutheria | 6 | 80 | 16 | 57 | 159 | -0.27 | -5.38 | -49±121 | 4 | 1 | 1 |
| Theria | 0 | 49 | 2 | 6 | 57 | -0.28 | -3.31 | -276±1148 | 3 | 1 | 0 |
| Amniota | 1 | 6 | 1 | 0 | 8 | -0.09 | -5.70 | -245±653 | 13 | 1 | 1 |
| Tetrapoda | 0 | 18 | 1 | 7 | 26 | -0.12 | -0.41 | -87±172 | 3 | 2 | 1 |
| Vertebrata (2R-WGD) | 4 | 509 | 14 | 45 | 572 | -0.21 | -3.5 | -125±1000 | 2 | 1 | 1 |
| Chordata | 1 | 95 | 2 | 2 | 100 | -0.12 | -4.56 | -80±320 | 2 | 1 | 1 |
| Deuterostomia | 0 | 10 | 0 | 1 | 11 | 0.06 | -0.86 | 14±84 | 1 | 1 | 1 |
| Bilateria | 0 | 125 | 4 | 4 | 133 | -0.10 | -2.67 | -8±387 | 2 | 1 | 1 |
NOTE: 2R-WGD, 2 rounds of whole genome duplication; RR, both paralogs are retrogenes; not-R, not a retroposition; auto→X, autosomal-to-X retroposition; X→auto, X-to-autosomal retroposition. B, M, F, stand for enrichment in brain, male, and female-specific expression (the average expression in selected tissues divided by the average expression in all tissues, both in TPM, for all transcripts mapping to genes assigned to the specific taxon of duplication by phylogenetic timing; the B set is as defined in S19 Table; M and F tissue subsets are as defined in Table 7). ± indicates standard deviation.
ΔBoE = BoEX - BoEautosomal; ΔTfbsNo = TfbsNo X - TfbsNo autosomal; ΔMAXIMAL = MAXIMALX - MAXIMALautosomal.