Saccharomyces cerevisiae was introduced as an experimental eukaryotic system for molecular biology mainly in the last two decades. Although of greater genetic complexity compared to bacteria, yeast is tractable by classical genetic techniques, a fact that enabled rapid progress in the molecular genetics of the organism. S. cerevisiae has then reached the forefront of experimental molecular biology since it was the first eukaryotic organism whose entire genome sequence has been made available.

 

Since then, yeast has proved to be a useful model to compare sequences of metazoan and made possible to identify mammalian ortologs in yeast cells. Thus: (a) YCF1, a gene which confers cadmium resistance shares a great sequence similarity with the human MRP1 and CFTR1 two members of the ATP transporter superfamily, in which mutations origin the cystic fibrosis disease (b) the understanding of amylodogenic disorders through the study of yeast prion biology has known considerable advances (c) PAT1 and PAT2, encoding the sub-units of the peroxisomal ATP-binding cassette required for the import of long-chain fatty acids into the peroxisome, are the yeast homologs of the human ALD gene.

 

Mutations in this gene are associated to X-linked adrenoleucodystrophy (ALD), a neurometabolic disease with a decreased ability to degrade very long chain fatty acids (VLCFA) and significant phenotypic variation. The highly conserved cellular functions from yeast to mammals associated with the ease of genetic manipulation opened the possibility to functionally dissect gene products from other eukaryotes and, in the “post-genomic era”, yeast was again at the forefront in functional genomics.