Monoclonal antibody raised against murine IL-1 alpha peptide cross-reacts with a 60-kDa antigen in early Drosophila melanogaster embryo.

Whole-mounts of Drosophila embryos were stained with the monoclonal antibody Vmp 18, raised against the peptide 199-208 of murine interleukin 1/ alpha. Immunofluorescence observations showed that the antibody cross-reacted with an antigenic determinant that changed in localization during Drosophila development. In syncytial Drosophila embryos, the antibody recognized an epitope localized on the nuclear envelope throughout mitotic division. As cellularization occurred, the fluorescence was mainly concentrated in the apical region of the blastoderm cells. Western blot analysis of whole Drosophila embryo extracts showed that the antibody recognized a 60-kDa protein in syncytial embryos and during germ band elongation. This suggests that the 60-kDa antigen undergoes dynamic redistribution during embryogenesis.