Figure 4. Diagram summarising the centromere number of anther cells at different early meiosis stages.

Bar represent the SEM. Centromere number in the pre-meiosis PMC cells (7.9±0.6) was nearly the same as in the anther somatic cells (8.6±0.2, P = 0.124 in one-tail t test); A centromere clustering event which brought down centromere dot number to 1.8±0.2 occurred at leptotene stage with the emergence of centromere blocks (indicated by arrow heads in Fig. 3. J, K); Centromere block number was maintained during zygotene (1.2±0.1 to 1.3±0.2, P = 0.737 in two-tail t test), but centromere dot number was increased to 2.8±0.3; Centromere blocks almost disappeared (0.3±0.2) at pachytene, and centromere dot number was further increased to 3.8±0.4, which is just about half of the centromere number in the anther somatic cells (8.6±0.2).