In situ labeling of granule cells for apoptosis-associated DNA fragmentation reveals different mechanisms of cell loss in developing cerebellum.
We have examined the role apoptosis plays during postnatal development of the mouse cerebellum by a new method utilizing T7 DNA polymerase for the in situ detection of DNA fragmentation associated with cell death. Granule cell loss between the third and fifth postnatal weeks, hypothesized to affect the granule cell to Purkinje cell stoichiometry, is not associated with DNA fragmentation. However, cerebellar granule cells undergo extensive nuclear DNA fragmentation between postnatal days 5 and 9. Cell death prior to synaptogenesis may help regulate granule cell number. Our results suggest that different mechanisms of cell death within the same neuronal cell population occur during development.
Biochemistry Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
K A
KA
Wood
B
B
Dipasquale
R J
RJ
Youle
D000375:Aging / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D002531:Cerebellum / Q000166:cytology* / Q000254:growth & development; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D004247:DNA / Q000187:drug effects / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology* / Q000254:growth & development
D003907:Dexamethasone; D004247:DNA