Embryos derived from egg chambers containing complete homozygous follicle cell clones are completely dorsalised.

wbl^RP/wbl^T6 flies are smaller than wbl^RP/+ flies.

Embryos derived from homozygous females are strongly dorsalised. Homozygous adults show reduced viability, the lethal phase being between the second and third larval instar stages. Transheterozygotes with wbl^M46, wbl^M88, wbl^T6, wbl^E4 or wbl^AR51 also have reduced viability, and embryos derived from these transheterozygous females are dorsalised and fail to hatch.

Dorsalised embryos. dec-1-marked clones restricted to the dorsal side of the follicular epithelium produce normal embryos with no defects in dorsoventral patterning. Clones on the dorsal side produce local dorsalisation of the embryo. Clones in the ventral anterior region yield embryos exhibiting anterior dorsalisation, clones in the ventral posterior produce result in dorsalisation of the embryo at the posterior.

Injection of snk^Δne.T:ea into the central region of homozygous embryos causes a lateralised/ventralised phenotype.

Embryos transplanted with perivitelline fluid from Tl² embryos exhibit a polar gastrulation. At the end of embryogenesis an almost complete restoration of pattern along the dorsoventral axis is seen. The point of injection determines the ventralmost point of the restored pattern.

Eggs derived from homozygous females cellularise normally but become abnormal at gastrulation. The embryos are dorsalised; a tube of dorsal cuticle is formed. Homozygous flies show a reduction in viability.