Abstract
Transpositions of the vector P[lArB] into the regions 78D, 61F, and 85F of chromosome 3, which result in various anomalies of mitoses in neural ganglions of homozygous larvae, were obtained by insertion mutagenesis. The tissue specificity of regulatory elements controlling the reporter gene was studied by staining for the activity of beta-galactosidase reporter gene of the vector P[lArB]. These regulatory elements are suggested to be the enhancers of the genes carrying insertions. In all studied mutants, staining for beta-galactosidase was found in tissues containing actively proliferating cells. The staining of germarium in adult female ovaries was the most pronounced. The germarium staining pattern was used for the identification of novel insertions leading to mitosis abnormalities. The P1003 (99F) insertion was found, which according to preliminary data leads to an increase in the mitotic index and anomalies of chromosome structure in neuroblasts of homozygous larvae. In addition, the 22w (42A) insertion leading to chromosome arrest in metaphase was found.