Synaptonemal complex-associated centromeres and recombination nodules in plant meiocytes prepared by an improved surface-spreading technique.

An improved method of preparing two-dimensional surface spreads of plant synaptonemal complexes (SCs) is described. This technique produces clear preparations of SCs and, in addition, consistently reveals both centromeres and recombination nodules (RNs) in PTA-stained preparations viewed by electron microscopy. A preliminary study of RN number and distribution in Allium fistulosum indicates that they faithfully reflect the positions of cross-over exchange events as revealed by chiasmata.