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Spermatogenesis and spermiogenesis in Ascaris lumbricoides Var. suum
Author(s) -
Goldstein Paul
Publication year - 1977
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051540302
Subject(s) - biology , prophase , spermatid , centriole , microbiology and biotechnology , telophase , metaphase , anaphase , prometaphase , chromatin , spermiogenesis , spermatocyte , mitosis , meiosis , spindle pole body , premature chromosome condensation , genetics , cell division , nucleus , spindle apparatus , chromosome , sperm , cell , dna , gene
Reorganization of the prophase I nucleus marks the beginning of the first meiotic division. A pair of centrioles is present at each pole at metaphase I and mitochondria are not observed in the spindle area. A chromosomal pellicle, which resembles a kinetochore plate but has no apparent association with microtubules, surrounds each autosome at metaphase I and II. The sex body lags behind the autosomes at anaphase I and segregates differentially to one daughter cell. Mitochondria and a pair of centrioles are present in the spindle during the second meiotic division. Localized condensation of chromatin and fusion of the condensed chromatin of the secondary spermatocyte telophase nucleus results in a compact spermatid nucleus. Loss of spermatid cytoplasm is effected by the ejection of a cytophore vesicle.