Over-expression of four copies of the br Z1 isoform (using a line containing both brBRcore.TNT.Q1.Z1.hs and brBRcore.Q1.Z1.hs) using heat shock at 5 hours after ecdysis to the second instar causes lethality at approximately 42-68 hours after the heat shock with no detectable third instar mouthhooks.
Animals carrying two copies of brBRcore.TNT.Q1.Z1.hs and two copies of brBRcore.Q1.Z1.hs that have been heat shocked between 45 and 52 hours after puparium formation (APF) form pharate adults with a transparent cuticle on many areas of the head, thorax and abdomen. The microchaetae and macrochaetae are present, and are sometimes slightly tanned. Dorsolateral areas of the abdomen sometimes show the beginning of adult melanisation that extends into the anterior region of the tergite where melanisation is not normally found. Animals carrying two copies of brBRcore.TNT.Q1.Z1.hs and two copies of brBRcore.Q1.Z1.hs that have been heat shocked between 30-35 hours APF show truncation of bristles on the head and thorax. Animals carrying two copies of brBRcore.TNT.Q1.Z1.hs and two copies of brBRcore.Q1.Z1.hs that have been heat shocked between 35-39 hours APF show truncation of bristles on the abdomen. Animals carrying two copies of brBRcore.TNT.Q1.Z1.hs and two copies of brBRcore.Q1.Z1.hs that have been heat shocked at 35 or 39 hours APF lack abdominal trichomes.
A 37oC heat shock causing expression of brBRcore.Q1.Z1.hs during the third larval instar or early prepupal stage results in lethality within a few hours of the heat shock. Heat shock induced expression of brBRcore.Q1.Z1.hs during late prepupal or pupal stages has no effect.
brBRcore.Q1.Z1.hs rescues brrbp-5
brBRcore.Q1.Z1.hs rescues brrbp-1
brBRcore.Q1.Z1.hs fails to rescue br28
brBRcore.Q1.Z1.hs fails to rescue br2Bc-1
brBRcore.Q1.Z1.hs fails to rescue br2Bc-2
brBRcore.Q1.Z1.hs fails to rescue br5
brBRcore.Q1.Z1.hs fails to rescue brnpr-3
brBRcore.Q1.Z1.hs fails to rescue brnpr-7
Z1 isoforms provide the rbp+ function in prepupal salivary glands.
The br Z1 protein isoform encoded by brBRcore.Q1.Z1.hs provides full rbp+ function.