Df(1)52 is hemizygous and homozygous lethal. Viability is rescued by P{w+4Δ4.3}.
Mutants arrest in mid embryogenesis. In combination with P{w+4Δ4.3} (which contains a cosmid that includes a number of genes within Df(1)52, but not roX2) fertile male offspring are recovered. These males are not developmentally delayed, are recovered in numbers consistent with full viability and appear normal.