Weakly ventralised phenotype. Hemizygotes and heterozygotes display strong head defects, internalised and disorganised filzkorper, internalised seventh and/or eighth abdominal segments and denticle belts are slightly expanded laterally. At 29^oC the ventralising effects are stronger: strong head defects, internalised and severely reduced filzkorper, internalised terminal abdominal structures and moderately laterally extended ventral denticle belts. Lethal when heterozygous with Df(2L)tkv2. Female transheterozygotes with tkv¹ and tkv⁶ are viable and display a wing phenotype, wing veins are very thick and short along the proximal distal axis.