mRNA expression and immunolocalization of peroxisomal proteins in PEX5 knock-out (Zellweger) mice

The PEX5 knock-out mouse fails to import matrix proteins into peroxisomes providing an 'excellent animal model for the cerebro-hepato-renal syndrome of Zellweger (Baes et al. 1997). We have investigated the expressions of peroxisomal matrix proteins and the corresponding mRNAs by immunohistochemistry (IHC) and in situ hybridization (ISH) during the fetal period and in newborn PEX5(-/-) mice compared to controls. The results of the present study show that the mRNAs for catalase (CAT) and acyl CoA-oxidase (AOX) are co-expressed in the same tissues and at a similar expression level in control and Zellweger mice. The localization of the corresponding proteins is cytoplasmic and nuclear in Zellweger versus peroxisomal in control animals.