Table 1. Frequency and severity of fragmented chromocenters in BrdtΔBD1/BD1 mutant round spermatids is background dependent.
In both backgrounds there is a statistically significant increase in the number of spermatids with fragmented chromocenters in the mutants (pValue ≤ 1.0×10-6 for B6 and ≤ 5.0×10-8 for 129). There is also a statistically significant difference in basal level of fragmented chromocenters between the two backgrounds (pValue ≤ 5.0×10-3). The difference in the number of fragmented chromocenters in the mutants of the two backgrounds is significant (pValue ≤ 5.0×10-7) as is the difference in the number of severely fragmented chromocenters (pValue ≤ 5.0×10-17).
| B6 +/+ | B6 ΔBD1/ΔBD1 | 129 +/+ | 129 ΔBD1/ΔBD1 | |
|---|---|---|---|---|
| Total nubmer of round spermatids (RS) per tubule of 100 tubules examined | 128.4±15.1 | 115.5±11.2 | 123.8±7.5 | 100.6±9.7 |
| RS with non-fragmented chromcenters (avr. per tubule of 100 tubules examined) | 119.5±13.1 | 84.3±6.9 | 104.3±5.4 | 33.5±4.0 |
| RS with fragmented chromocenters (avr. per tubule of 100 tubules examined) | 8.9±2.0 | 31.2±4.3 | 19.5±2.1 | 67.1±5.7 |
| RS with severely fragmented chromocenters (avr. per tubule of 100 tubules examined) | 0.2±0.1 | 6.4±0.8 | 2.6±0.6 | 55.1±4.6 |
| Percent of RS that have fragmented chromocenters (≥3 heterochromatin foci) | 7% | 23% | 17% | 67% |
| Percent of RS that have severely fragmented chromocenters (≥4 heterochromatin foci) | <1% | 6% | 2% | 55% |