[Mutagenesis, screening and characterization of mutants known as peroxisome biogenesis disorders in yeast]

Peroxisomes are essential for organisms' development and physiology. This fact is underscored by the lethality of a group of genetic disorders collectively known as the peroxisome biogenesis disorders (PBDs), such as Zellweger syndrome, in which peroxisomes fail to assemble properly. Defining the molecular bases of the PBDs has been the impetus behind the identification of the genes controlling peroxisome assembly, the PEX genes, from various modern organisms. Here as a original strain, Yarrowia lipolytica E122 was mutated by diethyl sulfate (DES) treatment and two mutants including temperature sensitive one were obtained. Compared to the initial strain, the two mutants showed more diffuse pattern of fluorescence characteristic of a cytosolic localization in immunofluorescence analysis, and showed no morphologically recognizable peroxisomes in electron micrographs. The two mutants arose from new gene mutation characterized by transformation and will be very useful in identification of new gene controlling peroxisome assembly from yeast.