[The effect of the pleiotropic action of single-locus (pp) and dual-locus (aapp) mutation of mink fur color genes on serotonin metabolism in the brain].

Specific features of serotonin (5-hydroxytryptamine, 5-HT) metabolism were studied in the brain of mutant sapphire minks, homozygous at genes determining silver-blue and Aleutian fur color (ppaa), and silver-blue minks (pp) in comparison with the standard-colored minks (++/++). In the midbrain of sapphire mutants, the activities of tryptophan hydroxylase (TPH) and monoamine oxidase (MAO), key enzymes of 5-HT biosynthesis and catabolism, were significantly higher; an increase in the 5-HT level was statistically nonsignificant due to considerable variation in this parameter; and the level of 5-hydroxyindole-3-acetic acid remained unchanged. A similar increase in TPH and MAO activities was also found in the midbrain of silver-blue pp minks, suggesting that activation of key enzymes of 5-HT metabolism in sapphire aapp minks is associated with the mutant alleles pp.