Figure 8.
Cell cycling and DNA synthesis in the htau mouse brain was detected with antibodies to PCNA and ki67 and by incorporation of the thiamine analog BrdU. No reactivity with the PCNA antibody was detected in wild-type mice (A) shown here at 14 months, but reactivity was detected in an age-matched htau mouse brain (B). Double labeling with PCNA (C, brown) and NeuN (C, purple) (a neuronal marker) showed that both neurons and glial cells expressed PCNA. Most cells that were positive for PCNA (D, brown staining) were not positive for CP13, reactive to phospho-serine 202 on tau (D, purple staining), with some rare exceptions. Incorporation of the thiamine analog BrdU (E, F, H, I), indicating DNA synthesis, was detected in some postmitotic brain regions of 12- and 18-month-old htau mice, including the somatosensory cortex (H, brown). Double labeling with antibodies to BrdU and ki67 (H, purple) revealed some cells that were positive for either marker and other cells that were positive for both (I).