Learn More
A technique has been developed for the separation of proteins by two-dimensional polyacrylamide gel electrophoresis. Due to its resolution and sensitivity, this technique is a powerful tool for the analysis and detection of proteins from complex biological sources. Proteins are separated according to isoelectric point by isoelectric focusing in the first(More)
Engrailed is required to establish and maintain developmental compartments within each segment of the fly. To understand the role of the engrailed protein in this process, we have raised antibodies against engrailed and have visualized an engrailed protein in embryos by indirect immunofluorescence. The protein accumulates in the nucleus, supporting the(More)
A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but(More)
The conserved regulators of cell cycle progression--Cyclins, Cdc2 kinase, and String phosphatase (Cdc25)--accommodate multiple modes of regulation during Drosophila embryogenesis. During cell cycles 2-7, Cdc2/Cyclin complexes are continuously present and show little fluctuation in abundance, phosphomodification, or activity. This suggests that cycling of(More)
A regulatory cascade, initiated during the syncytial stage of embryogenesis, culminates in the striped pattern of engrailed gene expression at the cellular blastoderm stage. The early regulatory genes, for example the pair-rule genes, are expressed transiently and as their products decay a distinct regulatory programme involving segment polarity genes takes(More)
We are examining the development of the segmental body pattern of Drosophila by immunolocalization of engrailed, a developmental regulatory protein that maintains segmental subdivisions in the embryo, and is expressed in a spatially restricted (striped) manner that persists while the body pattern is being established and refined. A regulatory network among(More)
In Drosophila embryogenesis, mitotic control undergoes a significant transition during the 14th interphase. Mitoses before interphase 14 run on maternal products, and occur in metasynchronous waves. Mitoses after interphase 14 require zygotic transcription, and occur asyncronously in an intricate, highly ordered spatio-temporal pattern. Mutations at the(More)
The cyclin proteolysis that accompanies the exit from mitosis in diverse systems appears to be essential for restoration of interphase. The early syncytial divisions of Drosophila embryos, however, occur without detectable oscillations in the total cyclin level or Cdk1 activity. Nonetheless, we found that injection of an established inhibitor of cyclin(More)
The string (stg) locus of Drosophila encodes a factor that is thought to trigger mitosis by activating the p34cdc2 protein kinase. stg is required for mitosis early in development and is transcribed in a dynamic pattern that anticipates the pattern of embryonic cell divisions. Here we show that differential cell cycle regulation during postblastoderm(More)