Table 2.
Chromosome missegregation in cyclin-B2-overexpressing MEFs is due to aurora A and PIk1 hyperactivity.
| (a) Normalization of PIk1 activity in cyclin-B2-overexpressing MEFs restores accurate chromosome segregation | |||||||
|---|---|---|---|---|---|---|---|
| MEF genotype (n) | Mitotic cells inspected |
% cells with segregation defects (s.e.m.) |
% metaphases with misaligned chromosomes (s.e.m.) |
% anaphases with chrom. bridges (s.e.m.) |
% anaphases with lagging chromosomes (s.e.m.) |
% anaphase failure (s.e.m.) |
% cytokinesis defects (s.e.m.) |
| Ccnb2T16 −Dox (3) | 65 | 13(1) | 1(1) | 5(3) | 4(2) | 2(2) | 0(0) |
| Ccnb2T16 +Dox (3) | 65 | 36(10)* | 7(4) | 9(3) | 15(4) | 3(3) | 2(2) |
| Ccnb2T16 −Dox (3) + BI | 69 | 19(3) | 0(0) | 10(3) | 7(1) | 2(2) | 0(0) |
| Ccnb2T16 +Dox (3) + BI | 77 | 14(1) | 3(1) | 6(2) | 3(3) | 3(1) | 0(0) |
| (b) Cyclin-B2-overexpressing MEFs in which PIk1 activity is normalized are not prone to aneuploidy | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEF genotype (n) | % aneuploid figures (s.e.m.) |
% (near) tetraploid figures (s.e.m.) |
Karyotypes with the indicated chromosome number |
||||||||||||
| 37 | 38 | 39 | 40 | 41 | 42 | 43 | 77 | 78 | 79 | 80 | 81 | 82 | |||
| Ccnb2T16−Dox (3) | 18(1) | 7(2) | 2 | 5 | 5 | 118 | 6 | 3 | 1 | 2 | 2 | 5 | 1 | ||
| Ccnb2T16 + Dox (3) | 39(1)*** | 7(1) | 3 | 2 | 22 | 89 | 13 | 6 | 4 | 1 | 2 | 5 | 3 | ||
| Ccnb2T16 −Dox(3)+BI | 21(1) | 8(0) | 3 | 5 | 9 | 114 | 7 | 4 | 3 | 1 | 4 | ||||
| Ccnb2T16 +Dox(3)+BI | 21(2) | 7(1) | 2 | 6 | 11 | 112 | 7 | 1 | 1 | 1 | 1 | 6 | 2 | ||
| (c) Normalization of aurora A activity in cyclin-B2-overexpressing MEFs prevents aneuploidy | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEF genotype (n) | % aneuploid figures (s.e.m.) |
% (near) tetraploid figures (s.e.m.) |
Karyotypes with the indicated chromosome number |
|||||||||||||||
| 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | |||
| Ccnb2T16 −Dox (3) | 17(1) | 8(1) | 1 | 2 | 8 | 119 | 5 | 1 | 1 | 1 | 1 | 2 | 2 | 6 | 1 | |||
| Ccnb2T16 +Dox (3) | 34(3)** | 11(1) | 5 | 5 | 14 | 96 | 12 | 2 | 3 | 2 | 3 | 3 | 4 | 1 | ||||
| Ccnb2T16 −Dox(3)+MLN | 23(1) | 8(1) | 5 | 4 | 13 | 109 | 6 | 1 | 1 | 2 | 6 | 2 | 1 | |||||
| Ccnb2T16 +Dox(3)+MLN | 22(2) | 8(3) | 4 | 5 | 11 | 112 | 5 | 1 | 1 | 1 | 1 | 2 | 5 | 2 | ||||
Asterisks mark values statistically different from −dox counterparts.
*
P<0.05;
**
P<0.01;
***
P<0.001.