The mms21-1 plants exhibit defects during meiosis. DAPI staining of meiosis stages from wild-type pollen mother cells. Various stages of meiotic chromosome spreads from wild-type (A–G) and mms21–1 (H-S) are illustrated (A, H) Leptotene stage. (B, I) Zygotene stage. (C, J) Pachytene stage. (D, K) Diakinesis stage. (E) Metaphase I. (F, L-N) Anaphase I. (G, O-S) Telophase II. Arrows indicate abnormal chromosomal fragments (I, M, O-R), chromosome bridges (N), and lagging chromosome (S). Bars = 10 μm.