The physiological role of the mitotic checkpoint protein Bub1 is unknown. To study this role, we generated a series of mutant mice with a gradient of reduced Bub1 expression using wild-type, hypomorphic, and knockout alleles. Bub1 hypomorphic mice are viable, fertile, and overtly normal despite weakened mitotic checkpoint activity and high percentages of aneuploid cells. Bub1 haploinsufficient mice, which have a milder reduction in Bub1 protein than Bub1 hypomorphic mice, also exhibit reduced checkpoint activity and increased aneuploidy, but to a lesser extent. Although cells from Bub1 hypomorphic and haploinsufficient mice have similar rates of chromosome missegregation, cell death after an aberrant separation decreases dramatically with declining Bub1 levels. Importantly, Bub1 hypomorphic mice are highly susceptible to spontaneous tumors, whereas Bub1 haploinsufficient mice are not. These findings demonstrate that loss of Bub1 below a critical threshold drives spontaneous tumorigenesis and suggest that in addition to ensuring proper chromosome segregation, Bub1 is important for mediating cell death when chromosomes missegregate.
Pubmed ID: 17938250 RIS Download
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Digital image processing system where microscope settings and processing steps may be adjusted in single user interface. Can acquire images from variety of cameras. Includes software package for capturing, archiving and preparing images for publication. Allows users to visualize and present images in several dimensions. Functionality of imaging toolbox expands constantly with wide range of different modules that are tailored to specific applications or microscope accessories. This resource is duplicated by SCR_018376
View all literature mentionsMus musculus with name C57BL/6J from IMSR.
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