Molluscan oogenesis

General morphological aspects of molluscan female reproductive tract and oogenesis, in particular vitellogenesis, are reviewed in this chapter. Most molluscan are dioecious with the gonad located in the posterior part of the animal. In general, oogenesis is localized in a welldefined ovary, in where...

Descripción completa

Detalles Bibliográficos
Autor principal: Arrighetti, F.
Formato: CHAP
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_97816311_v_n_p27_Arrighetti
Aporte de:
id todo:paper_97816311_v_n_p27_Arrighetti
record_format dspace
spelling todo:paper_97816311_v_n_p27_Arrighetti2023-10-03T16:44:33Z Molluscan oogenesis Arrighetti, F. General morphological aspects of molluscan female reproductive tract and oogenesis, in particular vitellogenesis, are reviewed in this chapter. Most molluscan are dioecious with the gonad located in the posterior part of the animal. In general, oogenesis is localized in a welldefined ovary, in where the growing oocyte is often in association with accessories cells that play an important role in its growth. Even though, in a number of species the transfer of nutrients from storage or digestive sites to the gonad has been proved. The disposition and number of accessory cells associated with single oocytes differ among molluscs and several functions have been attributed: synthesis and transfer of yolk precursor; synthesis and transfer of cytoplasmic organelles; the formation of egg envelopes; phagocytosis; hormone production; transportation of the oocyte. Oogenesis comprises a proliferative phase (premeiotic stage) followed by a growth phase (previtellogenic and vitellogenic stage). The vitellogenic stage is highly variable since the composition and organization of yolk differs among species and since different types of specialized cells may participate in the synthesis and transport of yolk or yolk precursors. The processes of yolk accumulation could be: autosynthetic, when yolk is synthesized by the oocyte itself; heterosynthetic when yolk is synthesized outside the oocyte ant then transported to it; or both. Mature oocytes display a wide range of egg envelope morphologies: primary envelopes are formed within the ovary, secondary envelopes are produced by accessory cells and tertiary envelopes formed by the accessory sex glands. © 2014 by Nova Science Publishers, Inc. All rights reserved. Fil:Arrighetti, F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. CHAP info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_97816311_v_n_p27_Arrighetti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description General morphological aspects of molluscan female reproductive tract and oogenesis, in particular vitellogenesis, are reviewed in this chapter. Most molluscan are dioecious with the gonad located in the posterior part of the animal. In general, oogenesis is localized in a welldefined ovary, in where the growing oocyte is often in association with accessories cells that play an important role in its growth. Even though, in a number of species the transfer of nutrients from storage or digestive sites to the gonad has been proved. The disposition and number of accessory cells associated with single oocytes differ among molluscs and several functions have been attributed: synthesis and transfer of yolk precursor; synthesis and transfer of cytoplasmic organelles; the formation of egg envelopes; phagocytosis; hormone production; transportation of the oocyte. Oogenesis comprises a proliferative phase (premeiotic stage) followed by a growth phase (previtellogenic and vitellogenic stage). The vitellogenic stage is highly variable since the composition and organization of yolk differs among species and since different types of specialized cells may participate in the synthesis and transport of yolk or yolk precursors. The processes of yolk accumulation could be: autosynthetic, when yolk is synthesized by the oocyte itself; heterosynthetic when yolk is synthesized outside the oocyte ant then transported to it; or both. Mature oocytes display a wide range of egg envelope morphologies: primary envelopes are formed within the ovary, secondary envelopes are produced by accessory cells and tertiary envelopes formed by the accessory sex glands. © 2014 by Nova Science Publishers, Inc. All rights reserved.
format CHAP
author Arrighetti, F.
spellingShingle Arrighetti, F.
Molluscan oogenesis
author_facet Arrighetti, F.
author_sort Arrighetti, F.
title Molluscan oogenesis
title_short Molluscan oogenesis
title_full Molluscan oogenesis
title_fullStr Molluscan oogenesis
title_full_unstemmed Molluscan oogenesis
title_sort molluscan oogenesis
url http://hdl.handle.net/20.500.12110/paper_97816311_v_n_p27_Arrighetti
work_keys_str_mv AT arrighettif molluscanoogenesis
_version_ 1807320933611864064