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The Ultrastructure of Mature Sperms of the Fresh-Water Snail Biomphalaria glabrata (Mollusca, Gastropoda)
E. W. Kitajima and W. L. Paraense
Transactions of the American Microscopical Society
Vol. 95, No. 1 (Jan., 1976), pp. 1-10
Stable URL: http://www.jstor.org/stable/3225346
Page Count: 10
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Mature sperm of Biomphalaria glabrata are cells 650 µm x 0.8 µm, with a short head and conical acrosome. There is a long middle piece, ending in a relatively short tail. The middle piece consists of a typical 9 + 2 axial complex, ensheathed by the mitochondrial derivative wound in a double helix, becoming single near the tail. The axoneme begins in a complex neck region, where coarse fibers appear fused with both the centriole and the peripheral tubules of the axoneme. The mitochondrial derivative has a paracrystalline material encasing a membranous core, in which a tubular channel is present. In negatively stained whole-mount preparations, the helical arrangement of the mitochondrial derivative and the ladder-like configuration of its membranous core are clearly seen. Enzymatic digestion with α-amylase and cytochemical tests demonstrated that the granules seen within the mitochondrial derivative and axoneme, as well as granules surrounding the axial complex at the tail region, consist of glycogen, which must serve as an endogenous source of energy. Short pronase treatment digested the axial complex of the sperm, but not that of the cilia of the seminal vesicle.
Transactions of the American Microscopical Society © 1976 American Microscopical Society