Expression of Ubx^hs.PG using heat shock results in different degrees of transformation of the wing, depending on the heat shock regime used. Cell morphologies range from those typical of the normal wing, to something resembling haltere tissue. Anterior wing cells, close to the margin, are in all cases more transformed than posterior cells, with a smooth gradient of transformation seen across the wing. In animals carrying one copy of Ubx^hs.PG, cell morphology is not dramatically affected, although the formation of hair pedestals is disturbed by early heat pulses (12-24 hours after puparium formation (APF) and 18-30 hours APF). More dramatic effects are seen in flies carrying two copies of Ubx^hs.PG. Late heat shocks (30 to 42 hours APF) prevent the formation of hair pedestals and significantly inhibit cell expansion, but are unable to produce the duplication of cell hairs normally seen in the haltere. Earlier heat shocks (24 to 36 or 18 to 30 hours APF) also cause cells to produce short and multiple hairs, and reduce cell expansion more dramatically. However, even in the most extreme cases (12 to 24 hours APF), transformed cells are not identical to typical haltere cells. Overexpression of Ubx^hs.PG during the pupal stage usually results in a marked reduction in wing size. Heat shock treatment before 20-24 hours APF prevents cell adhesion between the two wing surfaces, at least in the anterior part of the wing, leaving a hollow cavity filled with haemocytes. Heat shock treatment before 12-18 hours APF abolishes the differences in cell phenotype that characterise wing veins and interveins. Bristle morphology is affected in the treated wings, although neither the number nor position of bristles is altered. Overexpression of Ubx^hs.PG using heat shock as late as 30-42 hours APF transforms the wing type of sensillum in the dorsal radius into a sensillum with a pavilion (haltere type). Late heat shocks (18-30 hours APF) are better at inducing this transformation than early ones (12-24 hours APF).

Scr^C1 Antp^Ns-rvC3 Ubx^MX2 abd-A^M1 Abd-B^M8 larvae (deficient for activity of thoracic and abdominal homeotic genes) exhibit sclerotic plates anterior to each denticle belt. Expression of P{hsDfd}, P{hslab} or P{HSU} suppresses the differentiation of the sclerotic plates.

Expression induced 3, 4 or 5 hours after egg laying represses the formation of Keilin's organs almost completely in all segments. Induction at 7 or 8 hours has very little effect.

When heat shocked 4 hours after egg laying, a complete or almost complete pattern of ectopic A- and B- glial cells in T1-T3 develops. Heat shocks at 7 hours after egg laying have no effect.

Coexpression with Antp^hs.PHTA shows similar transformation to expression of Ubx^hs.PG alone. Coexpression with abd-A^hs.PS shows similar transformation to expression of abd-A^hs.PS alone, thought it is difficult to ascertain the phenotypic result as abd-A^hs.PS intermediate transformations resemble those of Ubx^hs.PG embryos.

tsh^hs.PdZ increases the expressivity of the homeotic transformations caused by Antp^hs.PHTA or Ubx^hs.PG.

Expression of Ubx^hs.PG by heat shock for 20 minutes at 4, 6, or 8 hours after egg laying results in larvae with profound alterations in head and thoracic morphology. Most of the larvae have three abdominal belts with A1 identity in the place of the head. The three thoracic segments are almost completely transformed into replicas of A1. On the ventral side and anterior to these transformed thoracic segments, there are three additional abdominal-like denticle belts, called C1, C2 and C3. Cirri, mouth hooks and the central part of the maxillary sense organs are associated with C2. The labial sense organ is associated with C3. The antennal sense organs, epistomal sclerite, labrum, ventral arms and T-ribs are associated with C1 or anterior to it. Any head structures that remain are on the ventral side of the larva. In Ubx^hs.PG embryos that are homozygous for Dfd¹⁶, Scr^C1, eve^unspecified, ftz^unspecified, tor^unspecified or ems³ the Ubx^hs.PG phenotype is altered.

Ubiquitous expression of Ubx at the late third instar causes almost complete lethality. The few survivors have rough eyes but none have the scar or sharp anterior boundary characteristic of ro^hs.PB flies.

Heat induction of embryos at 5-6 hours for 30 minutes causes transformation of the mandibular segment towards abdominal segment 1, shown by ventral denticles and dorsal spinules. Head involution is prevented. Incomplete transformation of thoracic segments to abdominal segment 1 identity. A heat shock of 1 hour causes transformation of the maxillary segment towards abdominal segment 1 as shown by a second belt of ventral denticles. Complete transformation of thoracic segments to abdominal segment 1 identity. A heat shock of 2 hours causes transformation of the labial segment towards abdominal segment 1 as shown by a third belt of ventral denticles located between the first two belts. Most cepahlic structures disppear so the larval head is composes of three segments with abdominal segment 1 identity. Heat shock in embryos deficient for other homeotic genes causes transoformation of all head, thoracic and abdominal segments towards abdominal segment 1. If the r protein of Abd-B is present parasegment 14 develops as wild type. If abd-A is present the thoracic pattern elements of os parasegments 7-13 disappear and acquire normal identities.

Heat induction causes transformation of thoracic segments to abdominal segment 1 identity.