Immunocytochemical study of YB-1 nuclear distribution in different cell types

• We examine distribution of YB-1 in the nuclei of different cells.
• Nuclear distribution pattern of YB-1 differs in different cell types.
• YB-1 may be a component of Cajal bodies in embryos, but not in other cells studied.
• YB-1 is partially colocalized with RNA polymerase I in some cell types.

In the present work we studied the distribution of YB-1 in the nuclei of mouse hepatocytes, early embryos and human skin fibroblasts with the use of light and electron microscopy. To reveal YB-1, we applied rat polyclonal antibody against the C-terminal fragment of YB-1 molecule and rabbit polyclonal antibody against full-length YB-1 molecule. YB-1 distribution patterns varied significantly in different cell types. YB-1 was found to be colocalized with RNA polymerase I in mouse hepatocytes and embryos. Besides, YB-1 was revealed in a population of Cajal bodies in 2-cell mouse embryos but not in other cells studied.