. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. AX. Figure 5. Schematic drawings of the Eplalre/ns btirgeri spermatozoon, (a) Whole view at low magnifi- cation; a, surface view; a', side view of the head, (b) Head and regions, (c) Acrosfjmal region indicated by a rectangle in the figure b. (d-g) A longitudinal and cross section of the flagellum. AV, acrosomal vesicle; AX, axoneme; DC, distal centriole; EP, endpiece; H, head; M. mitochondria; MP, midpiece; N, nucleus; NE. nuclear envelope; PC, proximal centriole; PM, plasma membrane; SM, subacrosomal material. the anterior
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. AX. Figure 5. Schematic drawings of the Eplalre/ns btirgeri spermatozoon, (a) Whole view at low magnifi- cation; a, surface view; a', side view of the head, (b) Head and regions, (c) Acrosfjmal region indicated by a rectangle in the figure b. (d-g) A longitudinal and cross section of the flagellum. AV, acrosomal vesicle; AX, axoneme; DC, distal centriole; EP, endpiece; H, head; M. mitochondria; MP, midpiece; N, nucleus; NE. nuclear envelope; PC, proximal centriole; PM, plasma membrane; SM, subacrosomal material. the anterior end of their heads, subacrosomal material between the acrosome and the nucleus, and a long per- foratorium rod through the nucleus (Follenius, 1965; Stanley, 1967; Nicander and Sjoden, 1971; Jaana and Yamamoto, 1981) (see Fig. 6b). When the sperm reach the outer chorion of the egg during fertilization (Nicander and Sjoden, 1971), or when they are exposed to fixatives (Jaana and Yamamoto, 1981), a long acrosomal process is formed. Spermatozoa of the elasmobranch Squalus sitckleyi. a species that has internal fertilization, have a cap-shaped acrosomal vesicle and a subacrosomal rod (Stanley, 1971). Spermatozoa of the sturgeon, Acipenser tninMiiontainis. which have a scalloped and cap-shaped acrosomal vesicle and filamentous structure in the sub- acrosomal material and in the canals through the nucleus, form an acrosomal process upon the acrosome reaction (Cherr and Clark, 1984). In Holostei (Afzelius, 1978) and Teleostei (Mattei, 1970), spermatozoa lack an acrosome. In hagfish, the act :>somal vesicle of thi spermatozoa covers the protrusion ol the nucleus with i -iderlying subacro- somal material (Figs. 3, 6). In our ^ reliminary experi- ments, the acrosomal exocytosis of the ^ptairems hurgeri sperm occurred not only at the apical point of the sperm head but at several points, and was not followed by con- spicuous formation of a long process. Such features are common in the
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
