A set of isogenic deficiency stocks created by FLP-induced recombination between FRT-carrying transgenic insertions; molecularly defined deletion endpoints correspond to initial location of the progenitor insertions. Initial core set of 209 isogenic deletions provides ~60% euchromatic genome coverage.
Newly formed primordial germ cells (PGCs) of wild-type stage 4 and 5 embryos (syncytial blastoderm and cellular blastoderm, respectively) are predominantly spherical. By contrast, similarly staged embryos from mothers heterozygous for Df(3L)ED4543 display a dominant phenotype in which most embryos (60-80%) include multiple PGCs with strikingly abnormal morphology. The cells have an irregular shape, often with small protrusions. In some cases, the protrusions appear to pinch off from the larger part of the cell. Often, the mutant PGCs are not as tightly coalesced as for wild-type. Instead of the one or two layers of closely packed PGCs, gaps sometimes appear between the PGCs, and the layered organization could be disrupted.