Ventral fate can be re-established by the injection of wild type cytoplasm. Areas expressing ventral genes form invaginations, with the shape of the invagination depending on the shape of the ectopic ventral gene expression. Long patches form furrows, round patches form pits. Cell shape in these furrows resemble the shapes in normal ventral furrows, though cells in round invaginations end up cone shaped.

Embryos from heterozygous females are strongly ventralised; the ventral epidermis is expanded, there is complete loss of dorsal epidermis and the mesoderm is not expanded. Females carrying Tl² in trans with a null allele of Tl produce dorsalised embryos.

Tl² embryos were used as donors of perivitelline fluid transplantation, the dorsalized embryonic phenotype facilitates easy removal of the perivitelline fluid.

Antimorphic when in combination with recessive alleles: heterozygotes have ventralized phenotypes, hemizygotes are lateralized and transheterozygotes are dorsalized.

dominant