Cytophotometric comparisons of DNA levels in neuronal and glial cells of the cerebellum: a comparative study.
Several cytochemical studies of the DNA content and ploidy status of neuronal cell nuclei in the central nervous system have reported the occurrence of hyperdiploid amounts of DNA in Purkinje cells and suggest the existence of some type of 'extra' DNA, the biological significance of which is, as yet, unknown. To explore this phenomenon further, the DNA content of glial and Purkinje cell nuclei was determined in several vertebrate species, using the DNA-specific fluorochrome 4',6-diamidino-2-phenylindole (DAPI) to stain isolated cerebellar nuclei for analysis with a single parameter flow cytometer. The Feulgen reaction for DNA was used to stain liver and cerebellar tissue imprints for the measurement of individual nuclei with a Vickers M86 integrating microdensitometer. In both types of analyses, chicken erythrocyte nuclei served as an internal reference standard of 2.5 pg DNA per cell. The mean DNA content of Purkinje cells and glial or granule cells was essentially the same as that found for diploid (2C) non-neuronal cells, such as hepatocytes, in rainbow trout, Amazon molly fish, salamander (Plethodon), mouse, rat, rabbit, cat, dog, monkey and human. Although Purkinje cell nuclei with 4C DNA levels were found in all of these species, except salamander and rabbit, the frequency of such cells was low (1-7%) and varied with the species. There was a low incidence of Purkinje cell nuclei with interclass DNA amounts in all species examined. Our data show that most neuronal cell nuclei in the cerebellum contain 2C levels of DNA.
D000818:Animals; D002415:Cats; D002467:Cell Nucleus / Q000032:analysis; D002531:Cerebellum / Q000032:analysis / Q000166:cytology*; D004247:DNA / Q000032:analysis*; D005399:Fishes; D005434:Flow Cytometry; D008099:Liver / Q000166:cytology; D009457:Neuroglia / Q000032:analysis; D009474:Neurons / Q000032:analysis; D011817:Rabbits; D051381:Rats; D013045:Species Specificity; D014337:Trout
D004247:DNA