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. Author manuscript; available in PMC: 2018 Mar 9.
Published in final edited form as: Cell. 2017 Mar 2;168(6):977–989.e17. doi: 10.1016/j.cell.2017.02.002

Figure 4. Female-specific CO maturation inefficiency: effects.

Figure 4

(A) Observed and predicted CO patterns on chromosome 21q. (i) Cartoon of predicted effects of CO maturation inefficiency on 21q bivalents with one (top) or two COs (bottom). (ii top): CO positions on single-CO bivalents as predicted by simulations to occur either: without any type of female-specific feature/deficit (green); with CO maturation inefficiency (purple); or with CO reduction by subtraction of active CO precursors prior to CO designation/interference (three different possibilities, gold, brown and orange; text). CO maturation inefficiency uniquely gives a broad distribution (purple) that matches the experimental distribution (II bottom; panel (iii) top) and results (II, middle) from the combined effects of single-designations with ensuing CO maturation (blue) or two designations, only one of which matures to a CO (red). Red open/closed bars: positions of COs in mis-segregation-prone bivalents (panel iii bottom). Red vertical arrows (top) and red asterisks (middle): contribution of CO maturation inefficiency to such bivalents. (iii) Experimentally-defined positions of COs along single-CO bivalents that have undergone either normal segregation (top) or mis-segregation (bottom) (adapted from Oliver et al., 2014). Mis-segregations are of two different types (filled and open vertical black bars). (B) Predicted frequencies of zero-CO bivalents for males and females, with and without CO maturation inefficiency (derived from Figure 3D). Arrow: position of chromosome 21. See also Figure S5.