Morphological Changes of Mammalian Nucleoli during Spermatogenesis and Their Possible Role in the Chromatoid Body Assembling

Figure 5

Ultrastructural analysis of Oryctolagus cuniculus germ epithelium. (a) Round spermatid with reorganized nucleolus (nu) and a large CB (*). (b) Round spermatids with reorganized nucleolus (nu) and CB (*) next to the acrosomal system (a). (c, d, and e) Elongated spermatids with reorganized nucleolus (nu) and large CB (*) linked to mitochondria aggregates (m) moving to the nuclear posterior region (n) where the development of mitochondrial sheath and spermatozoon tail will take place. (f) Spermatozoon in maturation process with no ribonucleoprotein accumulation. (n: nucleus; nu: nucleolus; *-chromatoid body; m: mitochondria; a: acrosomal vesicle). Bars = 10 μm.