Microtubule arrays in WT versus VF cdka;1/ − cdkd;3 mutants. (A–I) Confocal laser scanning micrographs of meiocytes expressing TagRFP:TUA5 (magenta) and REC8:GFP (green) from mid-prophase I to metaphase I in WT (A–C), VF cdka;1/− cdkd;3/+ (D–F), and VF cdka;1/− cdkd;3/− (G–I). Light-blue arrows indicate the half-moon configuration of microtubules present in WT that is lost in VF cdka;1/− cdkd;3/−. The yellow arrows highlight irregular spindles in metaphase I. (J, B′, E′, and H′) Pixel intensity quantification from three meiocytes at late prophase I in WT (B′ and blue lines), VF cdka;1/− cdkd;3/+ (E′ and green lines), and VF cdka;1/− cdkd;3/− (H′ and orange lines) of a section going through the middle of the meiocyte (white dotted line). (K–Q) After metaphase I, meiotic exit and dyad formation in VF cdka;1/− cdkd;3/− (Q), second meiotic division in WT (K–M) and VF cdka;1/− cdkd;3/+ (N–P). Red arrows indicate the midzone microtubule array. (R–X) Schematic representation (R) of simultaneous cytokinesis in WT, which is characterized by two perpendicular spindles at metaphase II and a tetrahedral tetrad (S and T), versus successive cytokinesis in VF cdka;1/− cdkd;3/+ mutant, in which the predominant spindle configuration is parallel, leading to a planar tetrad (U–X). (Y) Spindle orientation quantification for WT (n = 40) and VF cdka;1/− cdkd;3/+ (n = 36). Scale bar, 10 µm.