Since melanin is considered a virulence factor in Cryptococcus neoform
ans, its suppression at 37 degrees C has been perplexing. We now show
an opposite thermal regulation of superoxide dismutase (SOD), consiste
nt with a compensatory mechanism. Moreover, we demonstrate normal SOD
and catalase levels in albino, oxygen-sensitive mutants. These results
suggest that melanin is an antioxidant factor comparable in importanc
e to SOD.