A recessive X-linked mutation causing a 3-fold reduction in total body zinc content is widespread within Drosophila melanogaster laboratory strains. Fanis Missirlis¹, Negar Afshar², Bilge Argunhan², Lucia Bettedi², Joanna Szular². 1) Departamento de Fisiología, Biofísica y Neurociencias, CENTRO DE INVESTIGACIÓN Y DE ESTUDIOS AVANZADOS (CINVESTAV), Mexico City, D.F., Mexico; 2) School of Biological and Chemical Sciences Queen Mary, University of London Mile End Road, London, United Kingdom E1 4NS.

   A 3-fold increase in zinc accumulation was previously reported in fumble¹ heterozygous mutants and a deficiency strain uncovering the fumble locus (Gutiérrez et al., FEBS Letters, 584:2942). However, dietary interventions that changed systemic zinc content and genetic elimination of Metal Transcription Factor 1 had minimal impact on the fumble phenotype. Here we show that the fumble gene does not contribute to the substantial change in total zinc content between the aforementioned genotypes and multiple fly strains used as controls. Indeed, outcrossed fumble¹ heterozygous mutant flies with low zinc content were recovered. We excluded a purely maternal transmission of this trait and confirmed that the condition of low zinc is recessive and segregates with the X-chromosome. As several other Drosophila species tested have total body zinc concentrations in the range of 200 mg per g dry weight (Sadraie and Missirlis, Biometals, 24:679) we have concluded that the trait of low (approximately 70 mg per g dry weight) concentration of zinc is widely present in laboratory strains. We postulate this trait can be attributed to a single recessive mutation on the X-chromosome.