A chimaeric triple component construct was cloned into the binary vector pEND4K to allow the detection of animal promoter activity in plants. The construct comprised the bacterial reporter gene, GUS (beta-glucuronidase), flanked by the 5'- promoter of the rabbit uteroglobin (UG) gene and the 3' termination sequence of the octopine synthase gene. This hybrid was constructed by Bam HI digestion of the plasmid pUG400, to recover the 400-bp UG promoter. Subsequently, this 400-bp promoter fragment was cloned into the Bam HI site in place of the 35S promoter region of the plant expression vector, pKiwi101. The resulting recombinant, pUG400/GUS, was treated with Xba I and Xho I restriction endonucleases to isolate the whole construct which was finally cloned into the binary vector, pEND4K.