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Reproductive biology of colus stimpsoni prosobranchia buccinidae part 2 spermiogenesis


Veliger 21(1): 1-9
Reproductive biology of colus stimpsoni prosobranchia buccinidae part 2 spermiogenesis
In the early spermatid, nuclear material is coarsely granular and irregularly distributed. The centriole with associated axonemal fibers moves anteriorly through the center of the nucleus, within a cytoplasmic tube lined by the nuclear membrane. Migration terminates when the posterior nuclear membrane is subjacent to the anterior nuclear membrane and results in a cylinder of nuclear material surrounding the flagellar axoneme. The filamentous chromatin condenses into lamellae and the nucleus elongates. Elongation and condensation continue until the homogeneous, mature nucleus is formed. Acrosome formation is initiated in early phases of nuclear maturation. Fusion of Golgi vesicles results in a bluntly conical, early acrosome which is attached to a ring of electron-dense material associated with the Golgi lamellae. This electron-dense band of material separates from the acrosome during its migration to the anterior end of the nucleus. The mature acrosome, 0.4 .mu.m long, is conical and situated over the axoneme at the anterior end of the nucleus. Two mitochondrial derivatives at the posterior end of the nucleus appear to wrap around the axoneme and elongate posteriorly. The mature middle piece appears as a tightly packed, spiralled array of cristae surrounding the flagellar axoneme. The axoneme extends from the anterior end of the head, just beneath the acrosome, to about 2 .mu.m from the posterior end of the sperm and is surrounded by the nucleus in the head region. Tightly packed glycogen granules surround the axoneme in the principal piece. Mature sperm are about 140 .mu.m in length, with the nucleus measuring 100 .mu.m long, the midpiece about 10 .mu.m long and the principal piece about 30 .mu.m in length. Results from cytochemical techniques indicate that the nuclear proteins change from a lysine-rich protamine in the early and middle stages to an arginine-rich histone in the late and mature stages.


Accession: 006316410



Related references

Reproductive biology of Colus stimpsoni (Prosobranchia: Buccinidae). 2. Spermiogenesis. Veliger, 211: 1-9, 1978

Reproductive biology of colus stimpsoni prosobranchia buccinidae part 1 male genital system. Veliger 20(3): 266-273, 1978

Reproductive biology of colus stimpsoni prosobranchia buccinidae part 3 female genital system. Veliger 21(4): 432-438, 1979

Reproductive biology of colus stimpsoni prosobranchia buccinidae 4. oogenesis. Veliger 24(1): 28-38, 1981

Reproductive biology of Colus stimpsoni (Prosobranchia: Buccinidae). 5. Nutritive egg formation. Veliger, 254: 299-306, 1983

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Reproductive biology of Colus stimpsoni (Prosobranchia: Buccinidae). 1. Male genital system. Veliger, 203: 265-273, 1978

Histochemical and ultrastructural studies on spermiogenesis in colus stimpsoni prosobranchia buccinidae. American Zoologist 14(4): 1263, 1974

Nutritive egg determination in colus stimpsoni prosobranchia buccinidae. American Zoologist: 956, 1979

Notes on the development of colus stimpsoni prosobranchia buccinidae. Nautilus 87(1): 1-4, 1973