A birefringence, electron microscopy, and histochemical survey of chromosomal structure in the sperm nuclei of an echinothurid sea urchin, Araeosoma owstoni

Shonan Amemiya, Isao Uemura, Tadashi Shinkai, Hidemi Sato

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The mature sperm head of Araeosoma owstoni, an echinothurid sea urchin, showed positive birefringence reflecting that the overall orientation of DNA molecules was semiperpendicular toward the nuclear axis of the sperm head. Transmission electron microscopical observation of sperm in this species revealed a highly electron-dense cylindrical coil with an empty central core extending along the major axis of the sperm head. This coil had seven to eight turns along its entire length of 3.5 μm. The maximum width was 0.35 μm near the distal end of the nucleus, and the minimum width was 0.17 μm near the apical end. Lamellar substructures were also present in the sperm nucleus, appearing at the periphery of the electron-dense cylinder in a radial manner. Staining with Feulgen's reaction and acid-orcein indicated that the coil was probably composed of sperm chromosomes.

Original languageEnglish
Pages (from-to)446-453
Number of pages8
JournalExperimental Cell Research
Issue number2
Publication statusPublished - 1988 Dec


ASJC Scopus subject areas

  • Cell Biology

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