Etude cytochimique et ultrastructurale de l'�volution ovocytaire de Nereis pelagica L. (Ann�lide Polych�te)

Dhainaut, A.

doi:10.1007/bf00335690

Cited by 25 publications

(10 citation statements)

References 24 publications

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“…The incidence of abnormalities in cytology in such accelerated oocytes has been noted in N. diver sicolor (Clark and Ruston, 1963), P. dumerilii (Hauenschild, 1966), and N. grubei (Schroeder, 1971) ; and their ultrastructural basis has been described for Nereis pelagica (Dhainaut, 1970a), N. diversicolor and P. cultrifera (Dhainaut, 1970b).…”

Section: Discussionmentioning

confidence: 95%

Patterns of cerebral endocrine activity innereis diversicolor (annelida: Polychaeta)

AL‐Sharook

Golding

1979

Marine Behaviour and Physiology

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The brain of Nereis has a diversity of endocrine actions on processes associated with growth and sexual reproduction. Regeneration-promoting, maturation-inhibiting, and gametotrophic activities have been studied by transplating brains from animals at various stages of the life cycle into decerebrate, immature hosts. Endocrine activity declines greatly during gametogenesis. In animals approaching sexual maturity, maturation-inhibiting activity is extinguished, whereas a low but significant level of regeneration-promoting activity, and gametotrophic activity, is retained. The close correlation of these activities supports their postulated mediation by a single hormone, although the processes subject to endocrine control show different thresholds for hormone action.

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Section: Discussionmentioning

confidence: 95%

Patterns of cerebral endocrine activity innereis diversicolor (annelida: Polychaeta)

AL‐Sharook

Golding

1979

Marine Behaviour and Physiology

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“…The identification of a high molecular weight yolk protein precursor "Nereis vitellin" in Nereis virens (Fischer, 1979;Fischer & Schmitz, 1981;Fischer et ai., 1984) and Perinereis cultrifera (Baert, 1985(Baert, , 1986a has enabled the heterosynthetic pathway and incorporation into the oocyte of one type of yolk protein to be demonstrated (Fischer et al, 1984;Fischer & Dhainaut, 1985). A second, autosynthetic pathway of yolk protein formation has also been demonstrated in the Nereidae by the uptake of radio-labelled amino acids (and sugars for the synthesis of complex polysaccharides) (Dhainaut, 1967(Dhainaut, , 1969(Dhainaut, , 1970Dhainaut & Porchet, 1977a, 1977bDhainaut, 1984). An investigation into the biochemistry of yolk synthesis in Nephtys would clearly tell us a great deal, especially in the fight of the information we have available on the gonadotrophic hormone in this species (Olive & Bentley, 1980;Bentley, 1982;Bentley & Olive, 1982).…”

Section: Discussionmentioning

confidence: 97%

“…The ultrastructure of solitary oogenesis has been described in a number of polychaete species including Nereis diversicolor (Dhainaut, 1967(Dhainaut, , 1969a, Nereis pelagica (Dhainaut, 1970;Dhainaut & Porchet, 1977a, b), Nereis virens (Fischer & Dhainaut, 1985), (Fischer, 1975), and Arenicola marina (Rashan & Howie, 1982). In some cases, such as in Pla~nereis dumerilii (Fischer, 1975), there may be intimate contact of early oocyte stages with the follicle cells.…”

Section: Discussionmentioning

confidence: 99%

An ultrastructural study of oogenesis in the polychaeteNephtys hombergi Savigny

Bentley

1989

Helgolander Meeresunters

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The polychaete Nephtys hombergi has an annual cycle of reproduction. Ovaries were fixed for electron microscopy during the gametogenic phase from September to March, and during the breeding and post-breeding period. Oogenesis takes place entirely within the ovary, the integrity of which is maintained by a network of simple follicle cells. Previtellogenic oocytes have close contacts with the peri-vasal cells which surround the genital blood capillaries. These contacts are lost as the oocytes enter vitellogenesis. The vitellogenic oocytes have a cytology typical of oocytes which are thought to undergo autosynthetic production of protein yolk. Biochemical studies would be required to establish whether heterosynthesis of yolk also occurs. As the oocytes proceed through vitellogenesis, cortical material is laid down near the periphery of the oocyte and a microvillous surface is developed. When the microvillous surface is complete the oocytes, by then hormone independent, are ovulated from the ovary and are ready to be spawned.

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“…After fixation, they appear swollen and alveolar, containing filamentous material, which explains why they were termed cortical alveoli (Fallon and Austin 1967;Dhainaut 1969). They contain polysaccharides, including fucose and glucoronic acid (Dhainaut 1970a;Porchet and Spik 1978;Porchet 1984). Unlike vitellogenesis, corticogenesis appears to be an autosynthetic process.…”

Section: Corticogenesismentioning

confidence: 99%

Endocrine and environmental control of reproduction in Polychaeta

Andries¹

2001

Can. J. Zool.

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In Polychaeta, as in many invertebrates, reproduction is controlled by both environmental and endocrine factors. Although the effects of environmental factors on reproductive behaviour are briefly discussed, this review focuses on the endocrinology of reproduction. As Nereidae are the most intensively studied polychaetes, their epigamic monotelic strategy is discussed first in this review. Although a large number of physiological observations have been made, biochemical data have been greatly lacking until recent years, except, however, for the recent isolation of several pheromones. These substances, such as uric acid and L-cysteine gluthathione disulfide, occur widely and must be present at high concentrations in order to exert their physiological effects. Results obtained from iteroparous species are also considered. The stolonization strategy of Syllidae, the control of vitellogenesis in Nephtyidae, Phyllodocidae, Polynoidae, and Cirratulidae, and the regulation of gamete maturation in Arenicolidae and Pectinariidae are discussed. As with Nereidae, our knowledge of endocrine control is mainly based on experimental data, since only spermmaturation factor in the genus Arenicola has been identified. Therefore, despite numerous interesting experimental studies in which functional roles for polychaete reproductive hormones have been described, their nature, their primary targets, and their mechanism of action are unfortunately still largely unknown.Résumé : Chez les polychètes, comme chez de nombreux invertébrés, la reproduction est sous le contrôle de facteurs de l'environnement et de facteurs endocriniens. L'objet essentiel de cette synthèse est le contrôle endocrinien de la reproduction; des données plus fragmentaires ont trait aux effets des facteurs environnementaux. Puisque les Nereidae sont les polychètes les mieux connus, l'étude de leur stratégie monotélique épigame est envisagée dans un premier point. Toutefois, malgré de nombreuses observations physiologiques, peu de données biochimiques sont disponibles, si l'on excepte l'isolement récent de plusieurs phéromones. Celles-ci, comme l'acide urique et le disulfure de L-cystéine glutathion, sont des substances ubiquistes qui, de ce fait, doivent être présentes en concentrations élevées afin de pouvoir exercer une action physiologique. Les résultats obtenus chez les espèces itéropares font l'objet d'un second point. La stratégie de stolonisation des Syllidae, le contrôle de la vitellogenèse des Nephtyidae, des Phyllodocidae, des Polynoidae et des Cirratulidae, ainsi que le contrôle de la maturation des gamètes des Arenicolidae et des Pectinariidae sont examinés. Comme dans le cas des Nereidae, notre compréhension du contrôle endocrinien repose essentiellement sur des données expérimentales. Seul est identifié le facteur de maturation des spermatozoïdes d'Arenicola. Ainsi, malgré les nombreuses études expérimentales réalisées chez les polychètes et les multiples actions hormonales décrites dans les processus de reproduction, la nature des hormones, leurs cibl...

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Etude cytochimique et ultrastructurale de l'�volution ovocytaire de Nereis pelagica L. (Ann�lide Polych�te)

Cited by 25 publications

References 24 publications

Patterns of cerebral endocrine activity innereis diversicolor (annelida: Polychaeta)

Patterns of cerebral endocrine activity innereis diversicolor (annelida: Polychaeta)

An ultrastructural study of oogenesis in the polychaeteNephtys hombergi Savigny

Endocrine and environmental control of reproduction in Polychaeta

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