The inhibitory feedback mechanism coming from oocytes and acting on brain endocrine activity in Nereis (polychaetes, annelids)

Porchet, M.; Cardon, C.

doi:10.1016/0016-6480(76)90090-3

Cited by 15 publications

(9 citation statements)

References 18 publications

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“…Production and/or release of the inhibitory cerebral hormone is inhibited in maturing females (Porchet & Cardon 1976, Porchet et al 1979 and the whole system is in effect a 'positive feedback' system in which developing oocytes come to suppress the production of the hormone(s) that inhibit their further development. This culminates in a normally irreversible transition to the fully mature state.…”

Section: Endocrine Transduction Of the Environmental Signalsmentioning

confidence: 99%

Influence of photoperiod and temperature on oocyte growth in the semelparous polychaete Nereis (Neanthes) virens

Olive¹,

Rees²,

Djunaedi³

1998

Mar. Ecol. Prog. Ser.

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Environmental factors influencing the rate of oogenesis in the seasonal cycle of the semelparous polychaete Nereis (Neanthes) virens Sars have been investigated in specimens reared under commercial conditions (concrete tanks under natural light supplied with a mixture of power station heated and ambient sea water to maintain ca 18°C all year round). The rate of oocyte growth is strongly influenced by the external photoperiod and the responses to static 24 h LD (light-dark) cycles have been investigated. Oocyte growth is more rapid when specimens are exposed to a 24 h LD cycle in which the photophase is below a critical value between 1 2 and 13 h The critical photopenod transition in natural environments is therefore at the autumn equinox hr. rJirens are able to respond to transfer between LD 16:8 h and LD 8 16 h at all times of the year, which suggests the operation of a continuously consulted system of photoperiod~c control. The rate of oocyte growth in co~llpetent specimens is a 11near function of the number of LD 8-16 h cycles experienced. The critical photopt!riod divides the solar year into 2 nearly equal periods, with the short day period (winter) favouring oocyte growth. There is a synergism between the effects of photoperiod and seasonally reducing temperature. During the cdlendar winter transition to LD 8:16 h or other LD cycles below the critical value initiates rapid oocyte growth whatever the temperature but in the calendar summer this only occurs if the external temperature is also reduced to 12OC or below. The response to photoperiod and temperature is moderated by internal factors and under commercial production systems elevated rates of oocyte growth can only be achieved in females that are about 1 yr old. The oocyte growth induced by exposure to LD 8:16 h light cycles and low temperature is similar to, but slightly less than, that induced by hormone depnvatlon, i.e. supra-oesophageal ganglion ablation. The results are discussed in relation to the control of seasonal cycles in Nereidae, the role of the endocrine system and ~n the context of the life history theory for long lived semelparous organisms with variable age at maturity

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Section: Endocrine Transduction Of the Environmental Signalsmentioning

confidence: 99%

Influence of photoperiod and temperature on oocyte growth in the semelparous polychaete Nereis (Neanthes) virens

Olive¹,

Rees²,

Djunaedi³

1998

Mar. Ecol. Prog. Ser.

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“…The model also supposes that as more and more oocytes become mature and energy reserves are deployed in germinal tissue there is in turn an endogenously initiated loss of the capacity for further oocyte growth. A negative feedback exerted by the coelomic oocytes themselves would have the appropriate characteristics; such a system has been demonstrated, for example, in the Nereidae where maturing coelomic oocytes release a substance which inhibits the production of the maturation-inhibiting hormone (see Porchet & Cardon, 1976;Porchet & Spik, 1978), and in Cirratulidae, where maturing oocytes inhibit further production of oocytes by the ovaries (Olive, 1973), but a negative feedback alone cannot be the only factor involved since spawning or the completion of oosorption is not followed by an immediate recovery of the capacity for oocyte growth. Alternative bases for the proposed endogenous cycle are (i) the level of metabolic reserves, and (ii) a spontaneous rhythm of endocrinological activity.…”

Section: Group Vmentioning

confidence: 99%

Control of the Reproductive Cycle in Female Eulalia Viridis (Polychaeta: Phyllodocidae)

Olive¹

1981

J. Mar. Biol. Ass.

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Eulalia viridis (L.) is one of a group of polychaete species which are being used in an experimental analysis of the regulation of gametogenesis and reproduction. The back-ground to these studies and some of the preliminary results have been discussed recently by Olive (1980). Despite the abundant data demonstrating the frequent occurrence of well-defined reproductive cycles in marine invertebrates and observations on the correlations between reproductive events and environmental conditions, the mechanisms by which the reproductive cycles of individual species are controlled are very poorly understood. It has generally been accepted since the publication of the important paper of Orton (1920) that the temperature cycle in temperate and boreal regions plays an important role in determining the reproductive cycle, but the nature of the control mechanism is not, in general, understood and is likely to vary markedly between species. Environ-mental conditions such as relative daylength or biological factors such as the quantity and identity of the phytoplankton organisms (Himmelman, 1978, 1979) could also play important roles in regulating the sequence of cellular events which culminates in successful reproduction. These general problems have been discussed by Giese (1959) and more recently by Barnes (1975), Giese & Pearse (1975) and specifically in relation to Polychaeta by Clark (1979) and Olive (1980).

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“…In fact, the effect of transplanting submature oocytes differs according to the host's sex, inducing precocious maturation and epitoky in juvenile males but more or less abortive oocyte growth in juvenile females. The oocyte origin of the feedback substance was subsequently proved using extracts of submature and mature oocytes, which were found to be active both in vivo and in vitro (Porchet and Cardon 1976) (Fig. 1).…”

Section: The Feedback Substancementioning

confidence: 99%

“…To date, therefore, there is no doubt that a feedback substance exists. Unfortunately, neither its exact metabolic action on the nervous system nor its exact chemical identity is known, although it has been suspected to be a glycoprotein of low molecular weight (Porchet and Cardon 1976).…”

Section: The Feedback Substancementioning

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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The inhibitory feedback mechanism coming from oocytes and acting on brain endocrine activity in Nereis (polychaetes, annelids)

Cited by 15 publications

References 18 publications

Influence of photoperiod and temperature on oocyte growth in the semelparous polychaete Nereis (Neanthes) virens

Influence of photoperiod and temperature on oocyte growth in the semelparous polychaete Nereis (Neanthes) virens

Control of the Reproductive Cycle in Female Eulalia Viridis (Polychaeta: Phyllodocidae)

Endocrine and environmental control of reproduction in Polychaeta

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