Application of in situ hybridization, cytochemical and immunocytochemical techniques for the investigation of peroxisomes - A review including novel data

In situ hybridization, cytochemical and immunocytochemical techniques have contributed significantly to the understanding of the biology of peroxisomes, since they permit in situ demonstration of the sites of synthesis and distribution of peroxisomal proteins without the necessity of homogenization and subcellular fractionation of tissues or cultured cells. This article reviews the results of research on mammalian peroxisomal metabolism, biogenesis and proliferation in which morphological techniques have played a significant role in the elucidation of the biological problem. Some new data on peroxisomal heterogeneity and morphogenesis are included. The morphological methods applied have made it possible to characterize the differences in distribution of mRNAs encoding peroxisomal proteins in different tissues, as well as to monitor the marked heterogeneity in the protein composition and in the activity of specific enzymes in the peroxisomal population of single cells, or in tissues with complex organization (e.g. liver and kidney). In addition, the dynamic alterations and high plasticity of the peroxisomal compartment - partly dependent on contact of the peroxisomes to the microtubular network - are presented.