(A) XO pachytene oocyte with asynapsed X chromosome (arrow). SYCP3 (green) marks chromosome axes, γH2AFX (red) marks chromatin associated with asynapsed axes, and HORMAD1 (magenta, insets) marks asynapsed axes. (B) XO pachytene oocyte with self-synapsed X chromosome. The self-synapsed X chromosome (arrow) was identified by X chromosome painting (magenta, inset). (C) The mean percentage (± s.e.m.) of XO oocytes with a γH2AFX-positive or γH2AFX-negative X chromosome at pachynema, early diplonema and late diplonema. (D) In(X)1H pachytene oocyte with asynapsis (arrow). (E) In(X)1H pachytene oocyte with fully synapsed chromosomes. (F) Mean percentage of In(X)1H oocytes with γH2AFX-positive or γH2AFX-negative X chromosomes at pachynema, early diplonema and late diplonema. (G) T43H pachytene oocyte with asynapsed autosomes (arrow). (H) T43H pachytene oocyte with fully synapsed chromosomes, showing a trivalent involving the translocated chromosomes (arrow). (I) Mean percentage of T43H oocytes with γH2AFX-positive or γH2AFX-negative autosomes at pachynema, early diplonema and late diplonema. (J) XX pachytene oocyte with asynapsis (arrow). (K) XX pachytene oocyte with fully synapsed chromosomes. (L) Mean percentage of XX oocytes with γH2AFX-positive or γH2AFX-negative chromosomes at pachynema, early diplonema and late diplonema. P values were calculated from Tukey multiple comparison tests. Significant P values (P<0.05) are denoted by red font. Scale bar represents 10μm. (M) Schematic illustrating the possible outcomes for oocytes with chromosome abnormalities.

https://doi.org/10.1371/journal.pgen.1005753.g001