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Electron microscope studies of spermatogenesis in Branchiobdella pentodonta whitman (Annelida, oligochaeta)
Author(s) -
Bondi Carlo,
Farnesi Wsalba Maria
Publication year - 1976
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.1051480105
Subject(s) - biology , flagellum , acrosome , centriole , spermatozoon , microbiology and biotechnology , spermatogenesis , cytoplasm , anatomy , microtubule , meiosis , nucleus , nucleoplasm , electron microscope , synaptonemal complex , spermiogenesis , ultrastructure , semen , genetics , nucleolus , endocrinology , gene , optics , physics
In Brallchiobdella pentodonta Whitman meiosis begins in follicles containing 16 spermatogonia. In each follicle the spermatogonia are connected by cytoplasmic bridges to a central anuclear cytoplasmic mass or cytophorus. They develop synchronously. Synaptonemal complexes are present in the primary spermatocytes. Spermatids contain a large globoid paranuclear body consisting of an acrosomal granule and coiled tubules which evidently receive the contents of the acrosomal granule and are considered the acrosome carrier. The spermatids separate from the cytophorus only when differentiation is completed. The ripe spermatozoon is relatively long. It has anteriorly the coiled tubules, followed by the nucleus, the mitochondrial sphere and the distal centriole from which the flagellum originates, A coiled ribbon‐like structure encloses the flagellum along its entire length while a manchette of microtubules surrounds all the other structures of the sperm.