Construct: Alup\AFP1.5 3' untranslated sequences are replaced by Yp1 untranslated sequences.
Ice crystals in the haemolymph of P{YP1,2;wAFP2:YP1-3'} transgenic individuals grow into stable bipyramids. Ice crystals in nontransgenic individuals demonstrate unrestrained growth in the form of a circular plate. Adult survival trials at 0oC demonstrate that at 26 and 28 hours mortality of nontransgenic individuals is twice that seen in the transgenics, but there is no significant difference between the males and females of the transgenic line. Also males and females of the fly line Tm2 ry+ exhibit survival rates comparable to those of the transgenics at 0oC. These two lines of evidence suggest that the protective effect is not due to the transferred Alup\AFP1.5 and Alup\AFP1.9 genes.
Female transgenic flies bearing the construct synthesize Alup\AFP1.5 and secrete it into their haemolymph, male transgenics produce no Alup\AFP1.5 and serve as controls.