Disruption of selenoprotein biosynthesis affects cell proliferation in the imaginal discs and brain of Drosophila melanogaster.

The patufet gene encodes the Drosophila melanogaster homologue of selenophosphate synthetase, an enzyme required for selenoprotein synthesis, and appears to have a role in cell proliferation. In this paper we analyse the expression pattern of patufet during the development of imaginal discs and brain as well as the function of this gene in relation to cell proliferation. Wild-type organisms showed a highly dynamic pattern of ptuf mRNA expression during larval and pupal development. Co-localization analysis of ptuf mRNA expression and BrdU incorporation showed high levels of ptuf mRNA in dividing cells and low or undetectable levels in non-dividing cells. In addition, [(75)Se] incorporation revealed a major selenoprotein band of 42 kDa. Mutant organisms showed no selenoprotein synthesis, lower levels of cell proliferation, a higher proportion of cells arrested in G(2) as seen by cyclin B labeling and increased levels of reactive oxygen species (ROS). Because most selenoproteins identified so far are antioxidants, the role of ptuf in cell proliferation through the control of the cellular redox balance is discussed.