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 an tibody Vmp 18, raised against the peptide 199-208 of murine interleuki n 1/alpha. Immunofluorescence observations showed that the antibody cr oss-reacted with an antigenic determinant that changed in localization during Drosophila development. In syncytial Drosophila embryos, the a ntibody recognized an epitope localized on the nuclear envelope throug hout mitotic division. As cellularization occurred, the fluorescence w as mainly concentrated in the apical region of the blastoderm cells. W estern blot analysis of whole Drosophila embryo extracts showed that t he antibody recognized a 60-kDa protein in syncytial embryos and durin g germ band elongation, This suggests that the 60-kDa antigen undergoe s dynamic redistribution during embryogenesis.