Computational-aided identification of genes regulated by the Drosophila vnd

Neurogenesis in Drosophila melanogaster is initiated by an ordered appearance of neuroblasts arranged in three columns (medial, intermediate, and lateral) in the neuroectoderm. In each column, specific homeodomain-containing genes are expressed. The ventral nervous system defective (vnd) regulates the fate of the cells in the medial domain of the neuroectoderm. In the present study, we identified Vnd-regulated genes through computational screening. Through further screening, we selected eight genes that were downregulated in the vnd loss-of function mutation. These included zfh1, uzip, CG7687, SytIV, stau, ase, scrt, and dpn genes. Ectopic expression of vnd, using the GAL4/UAS system, caused abnormal expression of all eight genes. Further, eight genes were coexpressed with that of vnd. Reverse-transcriptase polymerase chain reaction (RT-PCR) experiments showed an enhanced expression of uzip, CG7687, SytIV, and ase. Although the other four genes did not show an enhanced expression through RT-PCR, cytochemical and genetic evidence showed that these genes were regulated by Vnd. Taken together, the results obtained from this study indicate that expression of at least four genes, uzip, CG7687, SytIV, and ase, are regulated by Vnd.