Table 7.
Summary of the origins of the 66 wheat ctDNA-homologous mtDNA segments
| MtDNA segment | Nature | Size (bp) | Genea) (ct/mt/Pm/Pu) | Originb) |
|---|---|---|---|---|
| 1a | Ortholog | 54 | trnQ/trnQ-1/trnQ/trnQ | Prokaryote |
| 1b | Paralog | 54 | - | (Copy of #1a) |
| 1c | Paralog | 54 | - | (Copy of #1a) |
| 2 | Ortholog | 77 | trnS-2/trnS-2/trnS/trnS | Prokaryote |
| 3 | Xenolog | 445 | - | Cereal |
| 4 | Xenolog | 69 | - | Cereal |
| 5 | Xenolog | 34 | - | Wheat |
| 6 | Xenolog | 36 | - | Wheat |
| 7 | Xenolog | 59 | - | Wheat |
| 8 | Xenolog | 58 | - | Recurrent (beta & cereal) |
| 9 | Xenolog | 29 | - | Wheat |
| 10 | Paralog | 328 | - | (Partial copy of #11a)c) |
| 11a | Xenolog | 1,110 | - | (Undetermined) |
| 11b | Paralog | 1,110 | - | (Copy of #11a) |
| 12 | Ortholog | 793 | aptA*/atp1*/atpA*/atpA* | Prokaryote |
| 13 | Xenolog | 526 | - | (Undetermined) |
| 14 | Xenolog | 446 | - | Recurrent (wheat & tobacco) |
| 15 | Xenolog | 210 | - | Wheat |
| 16 | Xenolog | 195 | - | Angiosperm |
| 17 | Xenolog | 220 | - | Monocotyledon |
| 18 | Ortholog | 116 | trnF/trnF/trnF*/trnF* | Prokaryote |
| 19a | Ortholog | 27 | -/trnF*/trnF*/trnF* | Prokaryote |
| 19b | Paralog | 27 | - | (Copy of #19a) |
| 19c | Paralog | 27 | - | (Copy of #19a) |
| 20 | Ortholog | 46 | trnC/trnF/trnC/trnC | Prokaryote |
| 21 | Xenolog | 32 | - | Cereal |
| 22 | Xenolog | 58 | - | Monocotyledon |
| 23 | Xenolog | 53 | - | Recurrent (cycas & cereal) |
| 24 | Ortholog | 73 | trnM/trnM/trnT/aldA | Prokaryote |
| 25 | Xenolog | 189 | - | Recurrent (wheat & tobacco) |
| 26 | Xenolog | 172 | - | Recurrent (wheat & tobacco) |
| 27 | Xenolog | 105 | - | Recurrent (wheat & tobacco) |
| 28 | Ortholog | 82 | trnW/trnW/trnW/trnW | Prokaryote |
| 29 | Xenolog | 61 | - | Angiosperm |
| 30a | Ortholog | 64 | trnP/trnP-1/trnP-1/trnP | Prokaryote |
| 30b | Paralog | 64 | - | (Copy of #30a) |
| 31 | Ortholog | 45 | -d) | Prokaryote |
| 32 | Xenolog | 176 | - | Wheat |
| 33 | Xenolog | 135 | - | Cereal |
| 34 | Xenolog | 120 | - | Monocotyledon |
| 35 | Xenolog | 370 | - | Cereal |
| 36 | Xenolog | 32 | - | Angiosperm |
| 37 | Xenolog | 30 | - | Angiosperm |
| 38 | Xenolog | 54 | - | Cereal |
| 39 | Xenolog | 4,319 | - | Cereal |
| 40 | Ortholog | 177 | -/rps12/rps12/rps12 | Prokaryote |
| 41a | Ortholog | 1,932 | rrn16/rrn18-1/rrn16/rrn16 | Prokaryote |
| 41b | Paralog | 1,932 | - | (Copy of #41a) |
| 41c | Paralog | 1,932 | - | (Copy of #41a) |
| 42 | Xenolog | 1,833 | - | Cereal |
| 43a | Ortholog | 3,145 | rrn23/rrn26-1/rrn23/rrn23 | Prokaryote |
| 43b | Paralog | 3,145 | - | (Copy of #43a) |
| 44 | Paralog | 69 | - | (Partial copy of #43a)e) |
| 45 | Ortholog | 65 | rrn23/rrn26*/rrn23*/rrn23* | Prokaryote |
| 46 | Ortholog | 86 | trnN/trnN/trnN/trnN | Prokaryote |
| 47a | Ortholog | 59 | trnN*/trnK-1*/trnN*/trnN* | Prokaryote |
| 47b | Paralog | 59 | - | (Copy of #47a) |
| 47c | Paralog | 59 | - | (Copy of #47a) |
| 48 | Ortholog | 65 | ndhF/nad5b/-/nuoL | Prokaryote |
| 49 | Xenolog | 67 | - | Cereal |
| 50 | Xenolog | 398 | - | Wheat |
| 51 | Ortholog | 39 | ndhA ex/nad1c/ndhSU/nuoH | Prokaryote |
| 52 | Xenolog | 43 | - | Green plant |
| 53a | Xenolog | 32 | - | Green plant |
| 53b | Paralog | 32 | - | (Copy of #53a) |
| 54 | Xenolog | 180 | - | Wheat |
| Total | Paralogs | 8,892 | 1.96%f) | - |
| ″ | Orthologs | 6,711 | 1.48%f) | - |
| ″ | Xenologs | 12,130 | 2.68%f) | - |
| Grand total | 27,733 | 6.13%f) | - | |
a) Orthologous genes found in the four genomes are indicated (ref. Table 5). *: Part of the gene sequence.
b) Origin of each paralog is shown as a copy of its postulated template in parentheses. Monocotyledons analyzed are all cereals: therefore, “monocotyledon” is synonymous to cereal. “Recurrent” origin means probable independent occurrence of the ctDNA transfer in the two or more species indicated in parentheses. “Cereal” means the occurrence of the ctDNA transfer in a common lineage of two or three cereal species.
c) Paralog of the 328 bp 5′-end of no. 11a mtDNA segment.
d) No genes in the wheat mt and ct genomes, and the cytidylate kinase and D amino acid oxidase gene in the Pm and Pu genome, respectively.
e) Paralog of the 69 bp 5′-end of no. 43a mtDNA segment.
f) The proportions (%) of the total mt genome (452,528 bp).