Expression of peroxisomal proteins provides clear evidence for the presence of peroxisomes in the male germ cell line GC1spg

Abstract

Peroxisomes are cell organelles that perform multiple functions in the metabolism of lipids and of reactive oxygen species. They are present in most eukaryotic cells. However, they are believed to be absent in spermatozoa and they have never been described in male germ cells. We have used the immortalized germ cell line GC1spg to investigate the expression of peroxisomal proteins in germ cells of mice. The GC1spg cells represent the differentiation state of type B spermatogonia or preleptotene spermatocytes. We could show that peroxisomal membrane proteins like Pmp70 and Pex14p as well as peroxisomal matrix proteins like catalase or acyl CoA oxidase are expressed in GC1spg cells. All these proteins were colocalized in the same structures within the cells. Furthermore, by electron microscopy we have identified subcellular particles with an ultrastructural appearance that is characteristic of peroxisomes. This is the first report demonstrating the peroxisomal compartment in male germ cells of mice.