Using the techniques of genetic engineering, a researcher has constructed a fusion gene containing the heat-shock response elements from a Drosophila hsp70 gene and the coding region of a jellyfish gene (gfp) for green fluorescent protein. This fusion gene has been inserted into the chromosomes of living Drosophila by the technique of transposon-mediated transformation. Under what conditions will the green fluorescent protein be synthesized in these genetically transformed flies? Explain.