منابع مشابه
Spermiogenesis in Lumbricus herculeus
Small pieces of the sperm sacs of Lumbricus herculeus were fixed for 4 hours in chrome-osmium, embedded in methacrylate, sectioned with a Porter-Blum microtome, and studied with a R.C.A. EMU-2C electron microscope. Each spermatid of a group developing synchronously is attached by a cytoplasmic strand to a common nutrient protoplasmic mass. This mass contains mitochondria and yolk bodies but is ...
متن کاملCytodifferentiation during Spermiogenesis in Lumbricus Terrestris
The structural changes during spermiogenesis were studied on developing spermatids in seminal vesicles and receptacles of Lumbricus terrestris fixed in glutaraldehyde-osmium tetroxide and embedded in Epon-Araldite. The centriole plays a prominent role in the morphogenesis and organization of the microtubules of the manchette and flagellum. Microtubules arising from the centriole extend anterior...
متن کاملDNA Barcoding Reveals Cryptic Diversity in Lumbricus terrestris L., 1758 (Clitellata): Resurrection of L. herculeus (Savigny, 1826)
The widely studied and invasive earthworm, Lumbricus terrestris L., 1758 has been the subject of nomenclatural debate for many years. However these disputes were not based on suspicions of heterogeneity, but rather on the descriptions and nomenclatural acts associated with the species name. Large numbers of DNA barcode sequences of the cytochrome oxidase I obtained for nominal L. terrestris and...
متن کاملSpermiogenesis in Cancer Crabs
Spermiogenesis in Cancer crabs was studied by light and electron microscopy. The sperm are aflagellate, and when mature consist primarily of a spherical acrosome surrounded by the nucleus with its short radiating arms. The acrosome forms by a coalescence of periodic acid-Schiff-positive (PAS-positive) vesicles. During spermiogenesis one edge of the acrosomal vesicle invaginates to form a PAS-ne...
متن کاملSpermiogenesis in birds
Current knowledge on avian spermiogenesis, including strengths and weaknesses, has been reviewed. Information on avian spermiogenesis considerably lags behind that in mammals because of the paucity of reports in birds. Spermiogenesis in passerine birds has received even much less attention than in non-passerine birds. Mechanisms underlying morphogenesis of the acrosome and nucleus, and roles of...
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ژورنال
عنوان ژورنال: The Journal of Biophysical and Biochemical Cytology
سال: 1959
ISSN: 1540-8140,0021-9525
DOI: 10.1083/jcb.6.1.45