Comparative observations on spermiogenesis
نویسندگان
چکیده
منابع مشابه
Observations on Spermiogenesis in the Fungus Gnat Sciara Coprophila
Although 9-membered centrioles are found in somatic tissues of Sciara, the centriole which lies at the spindle pole of the second meiotic division in male Sciara is composed of a row of approximately 70 short tubules in an oval array. Shortly after telophase of this unequal division, in the daughter cell destined to undergo spermiogenesis, microtubules become confluent with the tubules of the c...
متن کاملDrosophila spermiogenesis
Drosophila melanogaster spermatids undergo dramatic morphological changes as they differentiate from small round cells approximately 12 μm in diameter into highly polarized, 1.8 mm long, motile sperm capable of participating in fertilization. During spermiogenesis, syncytial cysts of 64 haploid spermatids undergo synchronous differentiation. Numerous changes occur at a subcellular level, includ...
متن کاملComparative observations on inorganic and organic lead neurotoxicity.
Environmental and occupational exposure to lead still generates concern, and recent studies have focused such concern on the role of body burden of lead during the fetal/neonatal period, especially in the genesis of disturbed central nervous system development. This discussion provides some comparative observations on the neurotoxicity of inorganic and organic lead species. The characteristics ...
متن کاملComparative Observations on the Near Eastern Epic Traditions
We must not doubt that stories were told and enjoyed long before humans learned how to transpose what the ear hears into what the eye sees. Whether brief or developed, transmitted verbatim or embellished, these tales were likely sung, chanted, intoned, or declaimed, with or without bodily accompaniments. Neither must we doubt that long before what we call writing (characters with visual codes) ...
متن کاملSpermiogenesis 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 کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bolletino di zoologia
سال: 1982
ISSN: 0373-4137
DOI: 10.1080/11250008209439379