This granule divides as the cell divides, so that each sperm has some part of it. Certainly there are some similarities at the EM level. This ring is usually only well preserved after freeze substitution. It is interesting that the plastids are active in division, because this suggest that maternal inheritance doesn't occur in ginkgo, and there would seem little point for the plastids to be dividing otherwise, as there would be no advantage in expiring energy away from the motility system. I'm not sure we can say the same thing for mitochondria.
Any comments welcome.
After division, during which the blepharoplasts are associated with the spindle poles, the blepharoplasts break up to form the spiral flagella band. The MLS is also present in motile stages of liverworts, Equisetum , and of course the cycads. On microtubules There can be little doubt that the microtubular band functions as an elastic cytoskeleton which maintains the overall shape of the mature gametes. As yet we cannot give any real details of the cytoplasmic events during sperm formation. For example it is clear that during development of the motile apparatus, MLS and nuclear metamorphosis, there are also sequential changes in other cytoplasmic organelles.