Full length pb gene is expressed from an Hsp70 promoter.
Expression of pbhs.PP using a 50 minute heat shock at 5.5 hours of development results in inhibition of germband retraction and head involution. Reduction of the T1 beard to less than or equal to 5 rows of denticles occurs in 95% of first instar larvae.
One 10-20 minute heat shock at 5 hours AEL results in inhibition of germ band retraction, inhibition of head involution and reduction of the T1 beard. Heat induced expression during third instar larval stage by administration of a 10 minute heat shock is very toxic. Survivors exhibit a number of leg phenotypes including tarsus-to-arista transformation at the ends of all tarsi. Ectopic expression of Scrhs.PP results in the formation of ectopic T1 beards in T2 and T3, coexpression with pbhs.PP suppresses T1 beard formation in all three thoracic segments. Ectopic coexpression of Scrhs.PP and pbhs.PP at 3 hours AEL does not affect the ectopic salivary gland phenotype caused by ectopic Scr expression alone.
Heat shock to embryos results in inhibition of germ-band retraction, inhibition of head involution, and a reduction of the T1 beard. One short heat shock of 15-30 mins between 64-72 hrs after egg laying causes shortening of the first leg, increase in the number of sex combs and induction of extra sex combs on the lower tarsal segment of the first leg.
pbhs.PP is a suppressor of larval mesothoracic segment phenotype of Scrhs.PP
pbhs.PP is a suppressor of larval metathoracic segment phenotype of Scrhs.PP
pbhs.PP is a non-suppressor of T1 beard | ectopic phenotype of Mmus\Hoxa5hs.PZ
pbhs.PP does not suppress the ectopic T1 beard in thoracic segment T2 and/or T3 phenotype seen in 98% of Mmus\Hoxa5hs.PZ first instar larvae treated with a 50 minute heat shock at 5.5 hours of development.