Transition from a meiotic to a somatic-like DNA damage response during the pachytene stage in mouse meiosis
Fig 6
Dotplot representation of RAD51 foci distribution.
(A) Analysis of RAD51 distribution by recovery time. Four substages were considered (MP: mid pachytene; LP: late pachytene; ED: early diplotene; LD: late diplotene). ANOVA analysis showed statistical differences (p≤0.0001) for the control and the three recovery times. In the control, MP cells have a high number of RAD51 foci but later-staged cells have little to none. A similar increase in the number of RAD51 foci is observed from LP to LD 1 hour after irradiation. Tukey's multiple comparisons test for individual comparisons showed statistical differences between MP and the rest of the stages, and also between LP and LD. Twenty-four hour after irradiation, the increase in the number of RAD51 is more obvious at all stages, while 72 hours after irradiation, the number of foci decreases from LP to LD. (B) Analysis of RAD51 distribution by cell stage. The number of RAD51 foci increases significantly in cells at all stages after irradiation (p≤0.0001). However, according to Tukey's test, the number of foci in irradiated mid-pachytene cells 1 hour after irradiation is not significantly different from control cells. At 24 hours, the number of foci increases in mid-pachytene cells and remains stable at 72 hours. This distribution departs from the pattern observed in cells at other stages, in which RAD51 increases slightly at 1 hour, peaks at 24 hours and then decreases at 72 hours. (ns: non-significant; *: p≤0.05; **: p≤0.01; ***: p≤0.001; ****: p≤0.0001). (C). Analysis of RAD51 foci associated (ON) or not associated (OFF) with SCs at early (blue) and late diplotene (brown). The distribution of both kinds of foci is similar, increasing at 1 hour, peaking at 24 hours and decreasing at 72 hours. Notably, the proportion of foci not associated with SCs (OFF) is higher in late diplotene spermatocytes.