[2] In late pachytene spermatocytes, a kind of Nuage appears to be associated with the nuclear envelope and intermingled with small vesicles, but not associated with mitochondria, and it is believed to provide precursor material for the CB.
By the late diplotene stage, prominent germ granule structures are disintegrated, but in secondary spermatocytes, the CB-like material aggregates again into large (0.5 mm) dense bodies.
After meiosis in step 1 round spermatids, these dense bodies aggregate and form one single big granule per cell, which is commonly called the CB.
The name CB derives from the fact that this cytoplasmic granule is strongly stained by basic dyes similarly to chromosomes and nucleoli.
The ring migrates to the caudal end of the developing middle piece of the flagellum, moving in front of the mitochondria that are engaged in mitochondrial sheath morphogenesis.