Abstract
We evaluated the expression of three yeast genes in Zygosaccharomyces rouxii using lacZ as a reporter gene; they were the gIyceraldehyde-3-phosphate dehydrogenase gene of Z. rouxii (GAP-Zr), that of S. cerevisiae (GAP-Sc) and the PHO5 gene of S. cerevisiae. The GAP-Sc promoter showed high expression in the Z. rouxii host as well as in the S. cerevisiae host. The GAP-Zr promoter showed a comparable level of expression as the GAP-Sc both in the S. cerevisiae host and the Z. rouxii host. The transcription initiation site of the GAP-Zr promoter in the heterologous host seems to be the same as that in the homologous host. The PHO5 promoter showed constitutive expression, as efficient as in the case of the GAP-Zr promoter, in the Z. rouxii host. All the promoters mentioned above can be used as sources of a high expression vector in the Z. rouxii host.