6.7% of heterozygous adults show at least one transformation phenotype.

Heterozygotes sometimes have transformations typical of bithorax or postbithorax mutants. The frequency of transformations is higher in flies in which the mutant allele is derived from the mother rather than the father, suggesting a maternal component. Homozygous embryos show mandibular malformations.

Slightly reduced pigmentation of fifth abdominal tergite in heterozygotes (Lewis, 1985). Adult trx^D/+ flies are viable and characterized by their 'bithorax variegated' phenotype (Lewis, 1985). These mutants show no prothoracic transformations, but do show patchy transformations of haltere into wing and third leg into second leg (as in bx and pbx) and variable transformations of posterior abdominal segments into more anterior ones (Capdevila and Garcia-Bellido, 1981; Duncan and Lewis, 1982). In homozygotes, deficiency heterozygotes, or transheterozygotes over trx¹, trx², or trx³, the trx^D allele is lethal or semi-lethal in larvae or pupae; in clones it is cell viable. Transformed trx^D/trx^D clones were found in the head region (but not in the thorax or abdomen) by Capdevila and Garcia-Bellido (1981), while transformed trx²/trx^D clones were found in both head and thorax (but not in the abdomen) by Ingham (1985b). dominant; lethal in homozygotes or with trx¹, trx², or trx³