Hsp83 sequences including 5' enhancer sequences, the promoter, the 5' untranslated region, the first exon, the intron and the first 111 codons of the open reading frame are fused to a truncated Ecol\lacZ gene (603bp of sequence). An internally deleted Hsp83 3' untranslated region (lacking the Hsp83 degradation element - HDE) is fused downstream of the Ecol\lacZ sequence. The nos translation control element (TCE) (nucleotides 1 to 185 of the 3' UTR) is also present downstream of the Ecol\lacZ sequence.