Change in length of synapsed bivalents during pachytene

Total pachytene bivalent length was measured in 93 nuclei from plants of an inbred line of maize (KYS). These nuclei are thought to represent samples of substages from the portion of pachytene which begins with the opening of the synizetic knot and ends with the initiation of loss of the synaptonemal complex at diplotene. Pachytene substages were ranked on the basis of the length of the anther in which they occurred, with longer anthers generally expected to contain more advanced stages. The data strongly suggest that maize synapsed bivalents shorten significantly during this period.