The development of fused- embryos of Drosophila melanogaster.

The mutant fused (1-59.5) belongs to a class of lethal mutations in Drosophila melanogaster that produce pattern duplications in every segment of the mature embryo. A study of the embryonic development of fused- embryos derived from fused- mothers shows that extensive cell death occurs early in development. This cell death accounts for the smaller size of the segments in fused- embryos. The pattern duplication observed is, probably, a secondary consequence of the pattern deletion.