Late stages of spermiogenesis in S. undulatus. (A) The nucleus (Nu) becomes homogenous in electron density and a nuclear lacuna (La) becomes evident. Manchette microtubules (Mm) continue to surround the nucleus and lipid droplets (Li) become present within the germ cell cytoplasm. Lipid inclusion (Li). (B) The nucleus (Nu) becomes highly elongate as the acrosome becomes highly compartmentalized. A protrusion of the nucleus, the nuclear rostrum (Nr), extends into the subacrosomal space (Sas). The subacrosomal space is separated from the acrosomal proper (Acp) by an acrosomal lucent ridge (Alr). (C) The nucleus (Nu) becomes more elongate and arched. The cytoplasm (Cy) and its organelles are forced under the arc of the nucleus. Acrosome (Ac). (D) The flagellum sets within the nuclear fossa (Nf) and begins to differentiate with mitochondria (Mi) and dense bodies (Db) surrounding the axoneme of the distal centriole. A fibrous sheath (Fs) also becomes present during this time.  

Contexts in source publication

Context 1

... the nucleus (Fig. 3A, Nu) becomes homogenous in elec- tron density, an electron lucent lacuna (Fig. 3A, La) is visible in many of the cross sections of the nucleus proper. Manchette micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal ...

Context 2

... the nucleus (Fig. 3A, Nu) becomes homogenous in elec- tron density, an electron lucent lacuna (Fig. 3A, La) is visible in many of the cross sections of the nucleus proper. Manchette micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal space. An acrosomal lucent ridge (Fig. 3B, Alr), historically termed the inner acrosomal ...

Context 3

... the nucleus (Fig. 3A, Nu) becomes homogenous in elec- tron density, an electron lucent lacuna (Fig. 3A, La) is visible in many of the cross sections of the nucleus proper. Manchette micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal space. ...

Context 4

... in elec- tron density, an electron lucent lacuna (Fig. 3A, La) is visible in many of the cross sections of the nucleus proper. Manchette micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal space. An acrosomal lucent ridge (Fig. 3B, Alr), historically termed the inner acrosomal membrane, separates the subacrosomal space (Fig. 3B, Sas) from the acrosomal proper (Fig. 3B, ...

Context 5

... sections of the nucleus proper. Manchette micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal space. An acrosomal lucent ridge (Fig. 3B, Alr), historically termed the inner acrosomal membrane, separates the subacrosomal space (Fig. 3B, Sas) from the acrosomal proper (Fig. 3B, ...

Context 6

... micro- tubules (Fig 3A, Mm) remain present as the nucleus elongates. The acrosome becomes further compartmentalized with the nuclear rostrum extending into the subacrosomal space. An acrosomal lucent ridge (Fig. 3B, Alr), historically termed the inner acrosomal membrane, separates the subacrosomal space (Fig. 3B, Sas) from the acrosomal proper (Fig. 3B, ...

Context 7

... late nuclear elongation the spermatid nucleus proper becomes curved, forcing the rough endoplasmic reticulum-filled cytoplasm (Fig 3C, Cy) to the inner radius of the germ cell. The developing flagellum is situated in the posterior nuclear indenta- tion, the nuclear fossa (Fig. 3D, Nf) and mitochondria (Fig. 3D, Mi) are associated with the flagellum, dense bodies (Fig. 3D, Db) sep- arate the individual mitochondria, and the fibrous sheath (Fig. 3D, Fs) is evident. ...

Context 8

... late nuclear elongation the spermatid nucleus proper becomes curved, forcing the rough endoplasmic reticulum-filled cytoplasm (Fig 3C, Cy) to the inner radius of the germ cell. The developing flagellum is situated in the posterior nuclear indenta- tion, the nuclear fossa (Fig. 3D, Nf) and mitochondria (Fig. 3D, Mi) are associated with the flagellum, dense bodies (Fig. 3D, Db) sep- arate the individual mitochondria, and the fibrous sheath (Fig. 3D, Fs) is ...

Context 9

... late nuclear elongation the spermatid nucleus proper becomes curved, forcing the rough endoplasmic reticulum-filled cytoplasm (Fig 3C, Cy) to the inner radius of the germ cell. The developing flagellum is situated in the posterior nuclear indenta- tion, the nuclear fossa (Fig. 3D, Nf) and mitochondria (Fig. 3D, Mi) are associated with the flagellum, dense bodies (Fig. 3D, Db) sep- arate the individual mitochondria, and the fibrous sheath (Fig. 3D, Fs) is ...

Context 10

... the spermatid nucleus proper becomes curved, forcing the rough endoplasmic reticulum-filled cytoplasm (Fig 3C, Cy) to the inner radius of the germ cell. The developing flagellum is situated in the posterior nuclear indenta- tion, the nuclear fossa (Fig. 3D, Nf) and mitochondria (Fig. 3D, Mi) are associated with the flagellum, dense bodies (Fig. 3D, Db) sep- arate the individual mitochondria, and the fibrous sheath (Fig. 3D, Fs) is ...

Context 11

... reticulum-filled cytoplasm (Fig 3C, Cy) to the inner radius of the germ cell. The developing flagellum is situated in the posterior nuclear indenta- tion, the nuclear fossa (Fig. 3D, Nf) and mitochondria (Fig. 3D, Mi) are associated with the flagellum, dense bodies (Fig. 3D, Db) sep- arate the individual mitochondria, and the fibrous sheath (Fig. 3D, Fs) is ...