Deleterious effect of null phenoloxidase mutation on the survival rate in Drosophila melanogaster

The effect of null activity of phenoloxidase on the survival rate was investigated in mutants of Drosophila melanogaster. Mox(GM95) and Dox-3(KD95), structural genes for prophenoloxidase A(1) and A(3), were found in natural populations in the former Soviet Union, and affected the phenoloxidase activity in active A(1) or A(3), respectively. After linking the visible markers located on the second chromosome together with the variants, cross experiments were performed to make homozygote, rdo Dox-3(KD95) pr c Mox(GM95) wt. No double mutant had emerged. In the mutant, c Mox(GM95) wt Pu-2, the viability was greatly reduced. These results suggested that phenoloxidase and tyrosine-3-hydroxylase act as indispensable proteins to maintain life in Drosophila. (C) 1999 Elsevier Science Ltd. All rights reserved.