The Relationship Between Dna Synthesis and Nuclear Proteins in the Cerebrum and Cerebellum of 8‐day‐old Rats

Abstract

In‐8‐day‐old rats the higher rate of DNA replication in cerebellum than in cerebrum is accompanied by an enhanced synthesis of nuclear proteins. The greatest difference between the incorporation of tritiated leucine into proteins of cerebral and cerebellar cell nuclei occurs in the acid‐soluble deoxyribonucleoproteins. However, the specific radioactivity of the acidic deoxyribonucleoproteins is similar in both tissues. The relative content of these proteins and the activity of the RNA polymerase is higher in cerebrum than in cerebellum. The results suggest that in the cerebrum of young rats these proteins are mainly concerned with the regulation of RNA synthesis.

Rna Polymerase Activity in Various Classes of Nuclei From Different Regions of Rat Brain During Postnatal Development

“…The Mn2'/(NH,),S0, stimulated reaction is greater in cerebellar nuclei during the first period of postnatal development, especially at 5 days of age, than in the other regions. This result is different from those obtained by BURDMAN et al (1973), who found a lower RNA polymerase activity in cerebellum of young rats. Possibly, this difference can be explained by the different yield of big neuronal and astrocytic nuclei during the purification procedure or by the different conditions of the assay of RNA polymerase activity.…”

Changes of CTP synthetase activity during postnatal rat brain development

“…1. Finally, it was clearly demonstrated that in both the 8-day-old (Burdman et al, 1973) and the adult rat (McEwen et al, 1972) the capacity for RNA synthesis per nucleus (i.e., per unit of DNA) was several times higher in the cerebrum than in the cerebellum, a result to be expected from our findings (see Fig. 3).…”