The Lamprey Egg at Ovulation (Lampetra fluviatilis L. Gray)

Larsen, Lis Olesen

doi:10.1095/biolreprod2.1.37

Cited by 20 publications

(5 citation statements)

References 12 publications

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“…Kobayashi and Yamamoto (1994) reported that in Lampetra japonica the layers were equal in thickness at the animal pole and in other regions the outer layer was thicker than the inner one. In the present study radial striations observed in chorion in the females under light microscope were not clearly seen by Larsen (1970), but were detected by Kille (1960) and in the electron study by Shalumovich and Shuvalov (1966) and by Afzelius et al. (1968).…”

Section: Discussionsupporting

confidence: 45%

“…In the lamprey, huge amounts of glycoconjugates (PAS and Alcian Blue positives) are accumulated in a peculiar tuft under the theca at the animal pole; a significant increase in the amount of the material was detected during the spawning run period (Larsen, 1970;present article). The tuft jelly is not sticky and is difficult to remove (Kille, 1960).…”

Section: Discussionmentioning

confidence: 93%

“…The chorion is composed of two layers; in the present study the inner layer at the animal pole was generally thicker than the outer layer, while in other regions the layers were similar in thickness. According to Larsen (1970), at the animal pole sometimes only the outer layer was thick, sometimes the inner, and sometimes both. Kobayashi and Yamamoto (1994) reported that in Lampetra japonica the layers were equal in thickness at the animal pole and in other regions the outer layer was thicker than the inner one.…”

Section: Discussionmentioning

confidence: 99%

“…In river lampreys maintained in the laboratory during the months of spawning migration Larsen (1970) reported the growth of several structures but gave numerical data only for the egg envelope. In the mature eggs the mean chorion thickness was 13.6 μm at the animal pole and 7.5 μm at the vegetative pole.…”

Section: Discussionmentioning

confidence: 99%

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Ripening of the oocyte of the river lamprey (Lampetra fluviatilisL.) after river entry

Dziewulska

Domagała

2009

Journal of Applied Ichthyology

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River lampreys (Lampetra fluviatilis L.) enter rivers for spawning with their gonads in the final stages of maturation, however the oocytes continue to develop until the spawn. This study was undertaken to depict detailed changes in the oocytes in the period approaching the spawn, using metric analysis and to look for atresia to determine if the time period influences the final fecundity. The study was performed on 37 females caught between October and May in the Rega River, north-western Poland. Mid-part sections of fixed ovaries were stained with Heidenhain haematoxylin and PAS. Ten cell structures of the oocytes were measured under light microscope with the aid of a computer image analysis programme. In the autumn, when the first lampreys entered the river, the nuclei of the oocytes were in the polar position. With the approaching mating season many oocyte structures changed significantly. Statistically significant (P < 0.001, Mann-Whitney U-test) was the increase in oocyte size (up to 1.06 · 0.78 mm in morphometric measurement), enlargement of the yolk platelets (f.a. 8.0 · 5.1 lm), elevation of theca over the chorion followed by the accumulation of glycoconjugates (f. a. 29.2 lm), growth of the zona granulosa at the vegetative pole (f. a. 24.2 lm), and increase in the thickness of the chorion at the animal pole (f. a. 11.1 lm). Other statistically significant changes (P < 0.05 and P < 0.01, Mann-Whitney U-test) included a decrease in the width of the cortical cytoplasm band (f. a. 20.5 lm), decrease in the ratio of the distance between the nucleus and cell membrane and the long axis of the oocyte (f. a. 7.6 lm), and increase in the thickness of the chorion at the vegetative pole (f. a. 6.0 lm). No statistically significant changes in the area of the nucleus and diameter of the cortical alveoles were noted. Beginning with the lamprey entering the river until the spawn, the oocytes undergo significant growth and maturation. In this period the fecundity of the lamprey decreased only slightly, as atresia was observed sporadically in the ovaries.

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Section: Discussionsupporting

confidence: 45%

Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Ripening of the oocyte of the river lamprey (Lampetra fluviatilisL.) after river entry

Dziewulska

Domagała

2009

Journal of Applied Ichthyology

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“…Ces lCsions, efficaces ou non, entrdnent la disparition du neuro-sCcrktat hypophysaire, mais aucune donnee ne concerne la cytoiogie adCnohypophysaire ; seuls 2 cas de lCsions inefficaces sont illustrCs qui montrent la persistance de nombreuses cellules gonadotropes aldChyde-fuchsine positives. Chez la Lamproie, (Lampetra fluviatilis L. Gray), l'hypophysectomie s'accompagne souvent d'ovulations anormales ou incompl6tes qui ne semblent pas corrigCes par l'autotransplantation du complexe << pro-mCsoadCnohypophyse > dans un cas (Larsen 1970).…”

Section: Discussionunclassified

Structure histologique de quelques glandes endocrines de l'anguille après autotransplantation de l'hypophyse

Olivereau

1971

Acta Zoologica

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Résumé L'étude histologique de diverses glandes endocrines et du rein est réalisée chez l'Anguille après autotransplantation de l'hypophyse dans la musculature dorsale et après hypophysectomie. La glande thyroïde est fortement hypoactive dans 25 pour cent des Anguilles greffées comme chez celles hypophysectomisées; elle est d'aspect subnormal ou normal chez les autres animaux où les cellules thyréotropes sont présentes dans le greffon. Malgré une variabilité plus grande que chez les témoins, dans aucun cas on ne peut parler d'une hyperactivité similaire à celle observée chez Poecilia. Comme le nombre des cellules thyréotropes est toujours réduit dans le transplant, il semblerait qu'une sécrétion basale de cette hormone suffise à maintenir une activité thyroïdienne notable. La fonction thyréotrope serait donc plus indépendante du contrôle hypothalamique que chez les Mammifères, sans que la notion de TIF (facteur inhibiteur) paraisse valable chez l'Anguille. L'interrénal est aussi très atrophié après hypophysectomie. Au contraire, après autogreffe, il conserve une structure proche de celle des témoins dans tous les cas, bien que moins homogène, malgré la réduction du nombre des cellules corticotropes dans le greffon. La vacuolisation cytoplasmique parfois notable pourrait indiquer un léger ralentissement de l'activité fonctionnelle de l'interrénal. Le contrôle hypothalamique ne semble donc pas s'exercer étroitement sur l'axe hypophyso‐surrénalien de l'Anguille. Les organes de Syrski restent très peu différenciés, en accord avec la régression des cellules gonadotropes dans le greffon, montrant la nécessité d'une stimulation d'origine hypothalamique pour le maintien de la fonction gonadotrope. Les corpuscules de Stannius sont similaires pour les 3 groupes d'Anguilles, l'hypophysectomie n'ayant pas d'effet net chez le mâle après 2 mois. L'atrophie rénale consécutive à l'hypophysectomie est fortement atténuée chez les Anguilles autogreffées, donnée qui suggère l'idée d'une sécrétion de prolactine par le transplant hypophysaire dont les cellules à prolactine apparaissent stimulées. En général, l'hypophyse déconnectée de l'Anguille conserve une autonomie fonctionnelle beaucoup plus marquée que chez les Vertébrés supérieurs, sauf pour la sécrétion gonadotrope. Abstract Histological structure of some endocrine glands in the eel after auto‐transplantation of the pituitary gland. The histological picture of various endocrines and of the kidney is described in control and hypophysectomized eels (Anguilla anguilla L.) and after autotransplantation of the pituitary in the dorsal muscle. The thyroid gland is greatly hypoactive in 3 grafted eels as well as in the hypophysectomized ones. It keeps a normal or subnormal picture in the other animals where thyrotrophic cells are still present in the graft. Although a higher variability is detected compared with control animals, in no case one can speak of a hyperactivity similar to that occuring in Poecilia. As the number of the thyrotrophic cells is always reduced in the transplant, ...

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Changes in brain gonadotropin‐releasing hormone, plasma estradiol 17‐β, and progesterone during the final reproductive cycle of the female sea lamprey, Petromyzon marinus

Bolduc

Sower

1992

J. Exp. Zool.

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Changes in ovarian morphology, brain gonadotropin-releasing hormone (GnRH), plasma estradiol, and progesterone were examined during the 1988 and 1989 spawning migrations of the adult female sea lamprey, Petromyzon marinus. There were significant increases through time in brain GnRH (1989) and plasma estradiol (1988 and 1989), with progesterone levels fluctuating (1988 and 1989) during the freshwater phase of the spawning migrations. In 1989, brain GnRH and plasma estradiol levels gradually increased through time until just prior to spawning when levels decreased. During 1988, there were no significant changes in GnRH, which may reflect lower temperatures in that year. These data provide new information on brain GnRH during the final maturational processes in the female sea lamprey.

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The Lamprey Egg at Ovulation (Lampetra fluviatilis L. Gray)

Cited by 20 publications

References 12 publications

Ripening of the oocyte of the river lamprey (Lampetra fluviatilisL.) after river entry

Ripening of the oocyte of the river lamprey (Lampetra fluviatilisL.) after river entry

Structure histologique de quelques glandes endocrines de l'anguille après autotransplantation de l'hypophyse

Changes in brain gonadotropin‐releasing hormone, plasma estradiol 17‐β, and progesterone during the final reproductive cycle of the female sea lamprey, Petromyzon marinus

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