The wingless product is required for cell proliferation in the Malpighian tubule anlage of Drosophila melanogaster

Abstract

Cell division in the Malpighian tubules of Drosophila melanogaster depends on the presence of a specialised cell at the tip of each tubule (Skaer, H. le B (1989) Nature 342, 566–569). Here we show that cell division also depends on the normal expression of the segment polarity gene, wingless. The pattern of wingless RNA and protein in developing tubules is consistent with a requirement for wingless for cell division. Analysis of the temporal requirement for wingless using a temperature- sensitive allele confirms that the normal expression of wingless is necessary during cell proliferation in the Malpighian tubules. Over-expression of the gene, induced in a stock containing the wg gene under the control of a heat-shock promoter, results in supernumerary cells in the tubules. We discuss the role of wingless in the cell interactions that govern cell division in the Malpighian tubules.