Table 3.
Peptides fragments of PR-10 isoforms in pollen from five Betula species as identified by Q-TOF LC-MSE.
| Species | Fragment | I | III | IV | V | VII | VIII | X | XVI | XVII | Sequence coverage | |
| Isoform | Gene | *2 | ||||||||||
| B. pendula | 01A01 | 1A | A | a | a | a | a | A | a? | a | a | 79% |
| 01A06 | 1A | A | a | a | b | a | A | a? | a | a | 79% | |
| 01B01 | 1B | B | B | a | b | a | C | B | a | a | 79% | |
| 01C04 | 1C | D | a | a | a | a | D | c? | a | a | 71% | |
| 01C05 | 1C | D | a | a | a | a | D | c? | a | a | 71% | |
| 01D01 | 1D | (E) | a | a | (C) | (C) | (E) | a? | a | a | - | |
| 02A01 | 2A | j | e | a | e | k | k | g? | (B*3) | a | 74% | |
| 02B01 | 2B | j | e | a | e | k | k | g? | (c*3) | a | 74% | |
| 02C01 | 2C | j | F | a | e | k | k | a? | (c*3) | a | 74% | |
| 03 *1 | (C), (z) | e | (z), (Y) | e | (Z), (y) | (z), (Y) | (z), (Y) | (z) | a | - | ||
| 04 *1 | (Y) | (Z) | (X), (W) | (Z) | (X) | (X) | (X) | (Y) | (Z), (Y) | - | ||
| 05 *1 | (X) | (Y) | (V) | (Y) | (W) | (W) | (W) | (X) | (X) | - | ||
| B. chichibuensis | 01var09 | 1A | a | a | a | a | a | d | a? | a | a | 79% |
| 01var12 | 1B | C | a | a | a | a | d | a? | a | a | 79% | |
| 01var17 | 1C | a | a | a | a | H | (H) | c? | a | a | - | |
| 01var18 | 1C | a | a | a | a | H | d | c? | a | a | 71% | |
| 01var19 | 1D | (E) | a | a | (C) | (J) | (E) | a? | a | a | - | |
| 02var03 | 2A | j | e | B | e | k | k | a? | (c*3) | a | 74% | |
| 02var08 | 2B | j | F | a | e | k | k | a? | (c*3) | a | 74% | |
| B. costata | 01var01 | 1A | F | a | a | a | a | c | a | a | a | 79% |
| 01var02 | 1B | a | a | a | a | a | c | a | a | a | 79% | |
| 01var04 | 1C | a | (C) | a | b | (E) | c | (D) | a | a | - | |
| 01var05 | 1D | a | a | a | b | a | c | (E) | a | a | 71% | |
| 01var13 | 1E | D | a | a | a | a | D | a | a | a | 79% | |
| Unknown | E | ? | ||||||||||
| 02var05 | 2A | j | (J) | a | e | k | k | a | (c*3) | a | - | |
| 02var10 | 2B | j | G | a | e | k | k | a | (c*3) | a | 74% | |
| Unknown | F | ? | ||||||||||
| B. lenta | 01var10 | 1A | G | A | a | (A) | (F) | d | a | (a*3) | a | 60% |
| 01var11 | 1A | G | A | a | (A) | (G) | d | a | (a*3) | a | 60% | |
| 01var16 | 1B | B | D | a | D | A | d | a | (a*3) | a | 74% | |
| 02var01 | 2A | j | e | a | e | k | k | a | (c*3) | a | 74% | |
| 02var04 | 2B | j | H | a | e | k | k | a | (c*3) | a | 74% | |
| 02var07 | 2C | j | F | a | e | k | k | a | (c*3) | a | 74% | |
| B. nigra | 01var03 | 1A | B | a | a | B | a | F | a | a | a | 79% |
| 01var06 | 1B | a | a | a | a | - | C | a | a | a | 74% | |
| 01var07 | 1C | a | a | a | a | a | C | a | a | a | 79% | |
| 01var08 | 1D | a | a | a | a | a | D | F | a | a | 79% | |
| 02var06 | 2A | J | K | a | e | K | K | a | (c*3) | a | 74% | |
| unknown | F | ? | ||||||||||
Each isoform is displayed on a separate line. When isoforms are encoded by the same gene this is indicated in the third column. Note that gene labels in one species do not correspond to gene labels in other species. Peptide fragments are shown at the top of the table and are labelled with Roman numbers as indicated in Fig. 3. Each variant of these fragments is displayed in the Table by a letter. Bold capital letters indicate that a fragment is unique for the isoforms of a particular gene. Bold italic letters indicate that a fragment is unique for the isoforms of a particular subfamily. Letters displayed between brackets indicate that a particular fragment was predicted, but was absent in the PR-10 mixture. Finally, the last column displays the coverage of the total protein sequence, including the fragments that were too small to be detected (II, VI, IX, XI, XII, XIII, XIV, XV). Fig. 3 displays the representative amino acid sequences of the isoforms 01A01 and 02A01.
*1 The isoforms in subfamily 03 to 05 were summarized into a single row and not displayed for the other species, because specific peptides were not detected in any of the species.
*2 Fragments Xa and Xg have exactly the same mass and cannot be distinguished. The peak of peptide Xc overlaps with the first isotope peak of peptide Xa = g because they differ exactly 1 Da in size and have the same charge. As a consequence, Xc cannot be identified separately.
*3 The XVI-peptides are not always detected because of their small size.