Estudo estrutural, ultra-estrutural e citoquimico da espermatogenese, com enfasena espermiogenese de Hyla ranki (amphibia, anura, hylidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1990

RESUMO

The present study was undertaken to determine morphologically, cytochemically and ultrastructurally the maturation process of spermatozoa Of Hyla rank. Histological and cytochemical.techniques where used with sections of material included in paraffin, as .well as observation of semi-thin and ultra-thin sections of testicles included 1n epan. Analysis of the results shawed that primary spermatogonia,through mitosis, originate spermatocysts were the germinative cells enter meiosis. As the resulting cells elangate, they organize themselves into sheths. Nuclear prateins are substituted as this elangatian praceeds and the substitution permits a strang crhamatin campactation in mature spermatazoa. The acrasame is ariginated.b_ fusian of Galgi vesicles a large acrasamal vesicle, which is considerably campacted as the spermatid elangates. The sperm tail presents an accessory structure consisting of basic prateins, in the shape of an . axial rad and cannected to the marginal filament and axaneme by an undulating membrane. The marginal filament, also made up of basic protein, follows the axoneme next to the 8th doublet of microtubules. The cytoplasmic processes involved in sperm maturation are intimately related with the activity of Sertoli cells1 which are observed from the earliest stage of spermatogonia until the formation of sperm sheathsl wyre the Sertoli cel1s surrounds each of sperm heads in the sheath. Slthough the morphological and cytochemical characterlstics of spermato2oa have been used as excluding systematic features to separate species, in the case of Hyla ranki and others of this group which have doubtful hylogenetical positions, our studysuggests that sperm chat-acterist ics should not be considered alone but rather together with other features of systematicvalue.

ASSUNTO(S)

anfibio - aspectos geneticos espermatogenese em animais citologia

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