Genotype of Wolbachia pipientis Endosymbiont Affects Octopamine Metabolism in Drosophila melanogaster Females

The effect of the genotype of the endosymbiont Wolbachia pipientis on the metabolism of octopamine (one of the main biogenic amines in insects) was studied in young Drosophila melanogaster females. The activity of tyrosine decarboxylase (key octopamine synthesis enzyme) and the activity of octopamine-dependent N-acetyltransferase (the enzyme of its degradation) were measured. It was demonstrated that the activity of both studied enzymes is increased under normal conditions in females infected with bacteria of the pathogenic wMelPop strain and decreased in those infected with bacteria of the wMelCS genotype, while it does not differ from those in uninfected flies in females infected with the wMel genotype. It was also found that the intensity of tyrosine decarboxylase response to heat stress is decreased in all females infected with Wolbachia. Thus, the effect of Wolbachia on octopamine metabolism was for the first time demonstrated in the Drosophila females, and it was shown that the nature of this effect is determined by the symbiont genotype.