CYTOCHEMISTRY AND IMMUNOCYTOCHEMISTRY OF NUCLEOLAR CHROMATIN IN PLANTS

This review attempts to document the most relevant data currently avai lable on the in situ localization of nucleolar chromatin on plant cell s. The data provided by the most powerful and recent in situ technique s, such as DNA specific ultrastructural staining, immunogold labelling , in situ molecular cytochemistry, in situ hybridization or confocal m icroscopy, are summarized and discussed in the light of the potential and limitations of each individual methodology. The presence of DNA in both fibrillar centres and regions of the dense fibrillar component i s extensively documented. Data on the nucleolar distribution of other important macromolecules involved in ribosomal transcription are also shown and referred to with regard to the location of DNA. The comparis on with the available data on the animal cell nucleolus points towards models of similar functional organization in both plant and animal nu cleoli.