NF-κB/Rel-Mediated Regulation of the Neural Fate in Drosophila

Two distinct roles are described for Dorsal, Dif and Relish, the three NF-κB/Rel proteins of Drosophila, in the development of the peripheral nervous system. First, these factors regulate transcription of scute during the singling out of sensory organ precursors from clusters of cells expressing the proneural genes achaete and scute. This effect is possibly mediated through binding sites for NF-κB/Rel proteins in a regulatory module of the scute gene required for maintenance of scute expression in precursors as well as repression in cells surrounding precursors. Second, genetic evidence suggests that the receptor Toll-8, Relish, Dif and Dorsal, and the caspase Dredd pathway are active over the entire imaginal disc epithelium, but Toll-8 expression is excluded from sensory organ precursors. Relish promotes rapid turnover of transcripts of the target genes scute and asense through an indirect, post-transcriptional mechanism. We propose that this buffering of gene expression levels serves to keep the neuro-epithelium constantly poised for neurogenesis

Newcastle disease virus infection in sparrows (Passer domesticus, Linneaus, 1758) captured in poultry farms of the agreste region of the State of Pernambuco

Reservoir competence for the Newcastle Disease virus (NDV) was evaluated in sparrows (Passer domesticus, Linnaeus 1758) captured on a commercial poultry farm and a chicken hatchery in the State of Pernambuco, Northeastern Brazil. A total number of 103 birds collected from a poultry farm (24/103) and a chicken hatchery (79/103) were examined. Hemagglutination inhibition tests, isolation, and viral characterization were performed in all samples collected from each bird. Titers ranging from 1:2 to 1:64 were detectable in 10.68% of sparrows, but positive serology and viral isolation were obtained only from sparrows captured at the hatchery. Hemagglutination activity was inhibited by anti-avian paramyxovirus serotype 1 (APMV-1) serum, and this sample showed an intracerebral pathogenicity index (ICOI) of 0.21, which is similar to the B1 stock vaccine (0.20) used for vaccination in those farms. Therefore, it was concluded that the sparrows were infected by stock vaccine virus, and that these birds could be a reservoir for NDV. However, additional studies involving sequencing of the virus genome of stock vaccine must be carried out