Electron spin resonance spectrometrical study of the melanins in the wool of some North European sheep in relation to their color inheritance.

Additional peaks that were known on the esr-spectrograms of red human and reddish-brown Karakul hair to be diagnostic traits of phaeomelanin esr-signal also were found on esr-spectrograms of the tan, but not of black or chocolate brown wool from Icelandic sheep. This tan color is thought to depend on the presence of phaeomelanin and is due to the top dominant allele at the A locus. The two methods of distinguishing between eu- and phaeomelanin-dependent brown colors--esr-spectrometrical and genetical--are in agreement for European as well as for Asiatic breeds. Both light and dark brown Soay fleece samples lacked the additional peaks and are interpreted as eumelanin pigmentation.