Table II.
Statistical Analysis of Data Obtained from Young and Aged rag2 Reporter NG Transgenic Mice
| Significance of differences | Younga | Ageda | p-value |
|---|---|---|---|
| No. of pro–B cells (millions)b | 1.0 ± 0.29 | 0.70 ± 0.12 | 0.035 |
| No. of pre–B cells (millions)b | 4.1 ± 1.0 | 1.3 ± 0.79 | 0.001 |
| Pre:pro ratioc | 4.0 ± 0.67 | 1.7 ± 0.94 | 0.001 |
| % of pro–B cells that are CD24high | 61 ± 4.1 | 45 ± 10 | 0.005 |
| % of pro–B cells that are GFP+ | 74 ± 2.7 | 45 ± 19 | 0.026 |
| Correlations b/t characteristics | n | r | p-value |
| % of pro–B cells that are GFP+ and no. of pre–B cells | 11 | 0.80 | 0.003 |
| % of pro–B cells that are GFP+ and pre:pro ratio | 11 | 0.88 | <0.001 |
Bone marrow from young (2–3.5 mo) and aged (26–27 mo) NG mice, and wild-type controls (both [FVBN × CBA]F1 background) was harvested and analyzed by flow cytometry and statistical analyses as described in Materials and Methods. In the NG mice, GFP is a reporter of rag2 expression.
Means ± SD are presented.
Numbers of pro–B (B220LOCD43+AA4.1+) and pre–B cells (B220LOCD43−AA4.1+CD24++) in bone marrow of young and aged NG mice were determined by multiplying the frequency by the leg bone marrow cell number determined by counting to obtain total numbers.
The pre:pro ratio was calculated by dividing the number of pre–B cells by the number of pro–B cells.
n, no. of mice; r, correlation coefficient.