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.