Genes for three Drosophila heat-shock-induced proteins at a single locus.

Two plasmids containing cDNA inserts complementary to the messenger RNAs for the 26,000 and 23,000 molecular weight heat-shock-induced proteins from Drosophila melanogaster were identified. Both of these probes hybridized to a site of a major heat-shock-induced puff, 67B. Hybridization by the gel transfer technique with genome DNA that had been cleaved by a restriction endonuclease indicated that the two genes are closely linked. This expectation was validated through isolation of a DNA fragment generated by BamHI endonuclease containing genes for the 26,000 and 23,000 molecular weight heat-shock-induced proteins and also a gene encoding the 27,000 molecular weight heat-shock-induced protein.