Fig. 10. (A-L) Overexpression of D2SV can sequester endogenous cyclin D2 (endo D2; A-C) and cyclin B1 (endo B1; D-F) or transfected cycD1 (tf D1; G-I) and cycB1 (tf B1; J-L) into aggregates. Transfected E14.5 cells were processed for immunostaining with antibodies specific for Myc (A,D,G,J), cycD2 (B), cycB1 (E,K) and cycD1 (H). Nuclei were counterstained with Hoechst stain (see merged images, C,F,I,L). The presence of colocalized protein aggregates in merged images in D, H and L is indicated by arrows. The arrowheads in A-C point to a D2SV aggregate that does not co-aggregate with endogenous D2. Scale bars: 20 µm. (M) Interaction of endogenous D2SV in whole embryo lysates with endogenous cell cycle proteins, IP, immunoprecipitation; Super, supernatant after IP; ab, antibody; LC, IgG light chain; HC, IgG heavy chain. (N) Co-expression of D-type or B-type cyclins with D2SV can increase DNA synthesis similar to the levels observed with vector-transfected or non-transfected cells. ^*P<0.005; D2SV versus other groups, n=3-6 experiments/group, 300–600 cells per group.