31. The mature r-proteins are then " imported " back into the nucleus and finally the nucleolus . 32. The best-known of these is the nucleolus , which is mainly involved in the assembly of ribosomes. 33. In this way, macromolecules with a molecular weight up to 2000 kDa are easily distributed throughout the nucleolus . 34. Treacle is active in the nucleolus , which is a small region inside the nucleus where rRNA is produced. 35. They are usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. 36. EBER1 associates with human ribosomal protein L22 and causes this protein to move from the nucleolus to the nucleoplasm. 37. The nucleolus is the largest sub-organelle within the nucleus and is the principal site for rRNA transcription. 38. A continuous chain between the nucleoplasm and the inner parts of the nucleolus exists through a network of nucleolar channels. 39. This collecting nucleolus was easily visible in phase contrast even without pretreatment due to its large size and particular structure. 40. The rRNA is transcribed, at a high speed, in the nucleolus , which contains all 45S rRNA genes.
