Expression of a 839bp fragment of Mmus\Hoxb9 cDNA encoding the entire 672bp open reading frame is driven by an Hsp70 fragment from position -225 to +65. Adh 3' flanking sequence contain nucleotides +1763 to +2502 and includes the polyadenylation site. Hsp70 and Adh sequences are present in "pHSBJ".
Heat induced expression during embryogenesis causes disruption of head involution. Anterior to thoracic segment 1 the embryo is expanded due to the non-involuted head segments that are transformed towards more posterior segmental identities (evidenced by the thoracic/abdominal denticles). Expression during early third instar causes partial antenna to leg transformation in adults. Heat induced expression during late third instar causes lack of ocellar bristles and ocelli. Also embryos exhibit a Ctx-like transformation, dorsal posterior head partially transformed toward dorsal thorax.
Heat induced expression during embryogenesis causes disruption of head involution. Anterior to thoracic segment 1 the embryo is expanded due to the non-involuted head segments that are transformed towards more posterior segmental identities (evidenced by the thoracic denticles and ectopic dorsal spinules). Expression during early third instar causes partial antenna to leg transformation in adults, arista segment becomes a tarsal segment.
