Table 2.
AHPO-HPLC data for individual melanin marker concentrations (ng/mg) in black, rufous and white feathers
| Eumelanin markers | Phaeomelanin markers | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feather type | HCl pre-treatment | PTCA | PDCA | PTeCA | PTeCA: PTCA | TTCA | TDCA | TTCA: TDCA | BZ-AA | 4-AHP | ||
| Black | Untreated | no |
1531 ± 203 |
138 ± 38 |
505 ± 87 |
0.33 ± 0.03 |
101 ± 31 |
75 ± 23 |
1.6 ± 0.96 |
8 ± 0.93 |
20 ± 14 |
|
| yes |
463 ± 111 |
83 ± 21 |
443 ± 79 |
1.01 ± 0.31 |
17 ± 5 |
54 ± 24 |
0.34 ± 0.08 |
X | X | |||
| 200 °C | no |
1427 ± 239 |
198 ± 50 |
521 ± 156 |
0.36 ± 0.06 |
69 ± 20 |
154 ± 54 |
0.46 ± 0.09 |
11 ± 2 |
28 ± 18 |
||
| 250 °C | no |
367 ± 133 |
226 ± 45 |
226 ± 75 |
0.66 ± 0.22 |
51 ± 15 |
109 ± 34 |
0.51 ± 0.22 |
140 ± 42 |
25 ± 9 |
||
| yes |
289 ± 85 |
108 ± 22 |
305 ± 77 |
1.07 ± 0.09 |
19 ± 7 |
64 ± 22 |
0.31 ± 0.1 |
X | X | |||
| Rufous | Untreated | no |
209 ± 62 |
86 ± 22 |
14 ± 4 |
0.07 ± 0.04 |
1032 ± 169 |
139 ± 63 |
9.2 ± 4 |
2598 ± 346 |
3907 ± 961 |
|
| yes |
59 ± 11 |
16 ± 5 |
9 ± 4 |
0.14 ± 0.05 |
356 ± 33 |
143 ± 27 |
2.6 ± 0.5 |
X | X | |||
| 200 °C | no |
146 ± 20 |
91 ± 55 |
21 ± 5 |
0.14 ± 0.02 |
1149 ± 350 |
555 ± 206 |
2.12 ± 0.22 |
1613 ± 383 |
1603 ± 553 |
||
| 250 °C | no |
80 ± 41 |
110 ± 24 |
45 ± 11 |
0.70 ± 0.3 |
673 ± 128 |
647 ± 108 |
1.03 ± 0.11 |
384 ± 102 |
185 ± 74 |
||
| yes |
100 ± 20 |
39 ± 11 |
56 ± 9 |
0.59 ± 0.17 |
612 ± 80 |
456 ± 77 |
1.4 ± 0.4 |
X | X | |||
| White | Untreated | no | 7 ± 1 | 2 ± 1 | 10 ± 3 | 1.5 ± 1 | 10 ± 4 | 3 ± 1 | 3.89 ± 2.47 | 8 ± 1 | 3 ± 2 | |
| yes | 3 ± 1 | 2 ± 0 | 3 ± 0 | 1.13 ± 0.33 | 8 ± 3 | 5 ± 1 | 1.59 ± 0.19 | X | X | |||
| 200 °C | no | 8 ± 0 | 5 ± 2 | 9 ± 3 | 1.22 ± 0.43 | 14 ± 8 | 4 ± 0 | 3.23 ± 1.81 | 8 ± 1 | 2 ± 1 | ||
| 250 °C | no | 24 ± 9 | 42 ± 17 | 19 ± 4 | 0.82 ± 0.12 | 23 ± 2 | 22 ± 5 | 1.09 ± 0.31 | 81 ± 36 | 16 ± 9 | ||
| yes | 73 ± 22 | 36 ± 6 | 43 ± 15 | 0.60 ± 0.11 | 11 ± 1 | 11 ± 5 | 1.24 ± 0.60 | X | X | |||
| Percentage change in marker concentration relative to untreated samples | ||||||||||||
| Black | 200 °C | no | −7 | +44 | +3 | +10 | −32 | +105 | −71 | +34 | +41 | |
| 250 °C | no | −76 | +64 | -55 | +99 | −50 | +45 | −69 | +1620 | +28 | ||
| yes | −37 | +31 | -31 | +5 | +14 | +19 | −10 | X | X | |||
| Rufous | 200 °C | no | −30 | −46 | +53 | +94 | +11 | +299 | −77 | −38 | −59 | |
| 250 °C | no | −62 | +29 | +231 | +855 | −35 | +365 | −89 | −85 | −95 | ||
| yes | +69 | +140 | +530 | +311 | +72 | +219 | −45 | X | X | |||
| White | 200 °C | no | +9 | +108 | -9 | −20 | +43 | +35 | −17 | 0 | -6 | |
| 250 °C | no | +251 | +1595 | +85 | −46 | +125 | +575 | −72 | +914 | +501 | ||
| yes | +2328 | +1934 | +1250 | −47 | +30 | +117 | −22 | X | X | |||
Mean and standard deviation data for individual melanin markers in untreated and experimentally matured black and rufous (each n = 5; Gallus gallus) and white (n = 4; Egretta garzetta) feathers following alkaline hydrogen peroxide oxidation (AHPO) and hydroiodic (HI) acid hydrolysis. Percentage data denote the mean change in concentrations of specific markers between untreated feathers and those matured at 200 °C and 250 °C. PTCA pyrrole-2,3,5-tricarboxylic acid, PDCA pyrrole-2,3-dicarboxylic acid, PTeCA pyrrole-2,3,4,5-tetracarboxylic acid, TTCA thiazole-2,4,5-tricarboxylic acid, TDCA thiazole-4,5-dicarboxylic acid, BZ-AA benzothiazole amino acid, 4-AHP 4-amino-3-hydroxyphenylalanine. Source data are provided as a Source Data file.