Megakaryocyte and platelet abnormalities in healthy young VavP-MYC mice
. | Bone marrow megakaryocytes . | . | . | Spleen megakaryocytes . | Platelets§ . | . | |||
|---|---|---|---|---|---|---|---|---|---|
. | No.* . | Size, mm† . | Internalized cells, %‡ . | No.* . | × 107/mL . | Vol, fL . | |||
| Wild-type, 2-4 wk | 4.7 ± 0.5 | 23 ± 2 | 2 | 3.6 ± 0.4 | 104 ± 13 | 5.3 ± 0.1 | |||
| MYC17, 2-4 wk∥ | 7.2 ± 0.5 | 46 ± 2 | 57 | 7.1 ± 0.6 | 20 ± 3 | 8.4 ± 0.6 | |||
| Wild-type, 5-7 wk | 6.2 ± 0.6 | 29 ± 1 | 0 | 1.9 ± 0.3 | 130 ± 7 | 5.8 ± 0.1 | |||
| MYC10het, 5-7 wk | 7.1 ± 0.4¶ | 38 ± 1∥ | 20∥ | 2.0 ± 0.3¶ | 113 ± 6¶ | 6.2 ± 0.1∥ | |||
| MYC10hom, 5-7 wk∥ | 9.5 ± 0.6 | 50 ± 2 | 58 | 3.4 ± 0.4 | 49 ± 3 | 7.1 ± 0.1 | |||
. | Bone marrow megakaryocytes . | . | . | Spleen megakaryocytes . | Platelets§ . | . | |||
|---|---|---|---|---|---|---|---|---|---|
. | No.* . | Size, mm† . | Internalized cells, %‡ . | No.* . | × 107/mL . | Vol, fL . | |||
| Wild-type, 2-4 wk | 4.7 ± 0.5 | 23 ± 2 | 2 | 3.6 ± 0.4 | 104 ± 13 | 5.3 ± 0.1 | |||
| MYC17, 2-4 wk∥ | 7.2 ± 0.5 | 46 ± 2 | 57 | 7.1 ± 0.6 | 20 ± 3 | 8.4 ± 0.6 | |||
| Wild-type, 5-7 wk | 6.2 ± 0.6 | 29 ± 1 | 0 | 1.9 ± 0.3 | 130 ± 7 | 5.8 ± 0.1 | |||
| MYC10het, 5-7 wk | 7.1 ± 0.4¶ | 38 ± 1∥ | 20∥ | 2.0 ± 0.3¶ | 113 ± 6¶ | 6.2 ± 0.1∥ | |||
| MYC10hom, 5-7 wk∥ | 9.5 ± 0.6 | 50 ± 2 | 58 | 3.4 ± 0.4 | 49 ± 3 | 7.1 ± 0.1 | |||
Mean frequency in tissue sections (± SEM) per high-power (× 400) microscope field. For each tissue, 20 to 48 fields were counted from 3 to 6 mice of each genotype and age. For MYC17 mice, the spleen was analyzed at 2 weeks and bone marrow was analyzed at 4 weeks. Note: the overall increase in splenic megakaryocytes in MYC mice is greater than suggested by these field counts because the average spleen size is larger than wild-type controls (3-fold for MYC17, approximately 1.3-fold for MYC10het, and 1.7-fold for MYC10hom mice). P for a t test.
Mean megakaryocyte diameter in tissue sections (± SEM); n = 60.
The percentage of megakaryocytes (n = 60) in tissue sections containing internalized cells (mainly intact granulocytes). The mean number of internalized cells per megakaryocyte section containing such cells was 2.6 ± 0.4 for MYC17, 1.2 ± 0.1 for MYC10het, and 2.1 ± 0.2 for MYC10hom.
Mean platelet counts (± SEM) and mean platelet volume (± SEM) in blood samples (n = 4-14).
P ≤ .001.
P ≥ .05.