Enzymatic basis for protection of fish embryos by the fertilization envelope

The mechanism by which the fertilization envelope (FE) is able to protect the embryo of fish until hatching is almost unknown, except for its function as a physical barrier. FE extract from activated or fertilized eggs of the fishSalmo gairdneri was demonstrated to contain enzyme activities using an agar plate enzyme assay. The enzymes apparently active were carboxymethylcellulase (cellulase; EC 3.2.1.4), laminaranase (endo-1,3(4)--glucanase; EC 3.2.1.6), carboxymethylchitinase (chitinase; EC 3.2.1.14), xylanase (endo-1,4--xylanase; EC 3.2.1.8), mannanase (mannan 1,2-(1,3)--mannosidase; EC 3.2.1.77), dextranase (EC 3.2.1.11), a protease and lysozyme (EC 3.2.1.17). The FE extract exerted an antifungal or fungicidal action on the fungusSaprolegnia parasitica, whereas an extract from the vitelline envelopes (VE) has no apparent enzyme activity nor antifungal or fungicidal action. Enzymes acquired by the FE through the cortical reaction may have an important defensive role, protecting the embryo against invaders or pathogens.     

Enzymatic basis for protection of fish embryos by the fertilization envelope.

The mechanism by which the fertilization envelope (FE) is able to protect the embryo of fish until hatching is almost unknown, except for its function as a physical barrier. FE extract from activated or fertilized eggs of the fish Salmo gairdneri was demonstrated to contain enzyme activities using an agar plate enzyme assay. The enzymes apparently active were carboxymethylcellulase (cellulase; EC 3.2.1.4), laminaranase (endo-1,3(4)-beta-glucanase; EC 3.2.1.6), carboxymethylchitinase (chitinase; EC 3.2.1.14), xylanase (endo-1,4-beta-xylanase; EC 3.2.1.8), mannanase (mannan 1,2-(1,3)-alpha-mannosidase; EC 3.2.1.77), dextranase (EC 3.2.1.11), a protease and lysozyme (EC 3.2.1.17). The FE extract exerted an antifungal or fungicidal action on the fungus Saprolegnia parasitica, whereas an extract from the vitelline envelopes (VE) has no apparent enzyme activity nor antifungal or fungicidal action. Enzymes acquired by the FE through the cortical reaction may have an important defensive role, protecting the embryo against invaders or pathogens.     

Uptake of tritiated glycine into neurons of the human retina

Résumé L'accumulation de³H-glucine de la rétine humaine a été étudiée autoradiografiquement. Comme chez les animaux inférieurs, la radioactivité s'accumulait surtout dans la couche plexiforme interne, dans la couche des filaments nerveux et dans des cellules ayant la position des amacrines. Les résultats doivent indiquer que la glucine peut être neurotransmetteuse inhibitive dans l'espèce diffuse des cellules amacrines de l'oeil humain et également dans d'autres cellules du système nerveux central de l'homme.     

A method of lipid injection into a fish egg

Zusammenfassung Mittelst Mikropipette von einem Spitzendurchmeser 15–20 werden Lipide in Fischeier injiziert. Die leichtere Löslichkeit der Lipide wird mit Olivenöl oder einem Gemisch Olivenöl/Rizinusöl erreicht. Unmittelbar nach der Befruchtung ist der Einspritzungserfolg am grössten.     

Uptake of catecholamines into serotonergic nerve cells as demonstrated by fluorescence histochemistry

Zusammenfassung Die histochemische Fluoreszenzmethode wird zum Studium der Nervenzellen des Gehirnstammes der Ratte angewandt. Die erhebliche Zunahme des Dopamins, hervorgerufen durch die Injektion eines peripher wirkenden Dekarboxylase-Hemmstoffes zusammen mitl-DOPA, wird im Gehirn verfolgt und gefunden, dass serotonergische Neuronen imstande sind, Catecholamine aufzunehmen.

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This work has been supported by the Clinical Research Center for Parkinson's and Allied Diseases, grant No. NS05184.     

Uptake of3H-noradrenaline and3H-5-hydroxytryptamine in cultured rat brainstem

Zusammenfassung Die zelluläre Lokalisation der Aufnahme von³H-NA und³H-5HT in den Hirnstamm von Ratten wurde am Modell der Nervengewebskultur untersucht. Im Gegensatz zu den Aminosäure-Transmittern, welche in Neurone und Gliazellen aufgenommen werden, zeigen Monoamine nur eine Aufnahme in Zellkörper und Fortsätze von Neuronen, nicht jedoch in Gliazellen. Es besteht eine Korrelation zwischen den Ergebnissen von fluoreszenzmikroskopischen Versuchen und unseren autoradiographischen Untersuchungen.     

Incorporation of thymidine into the chromosomes of aphid (Myzus persicae) embryos

Résumé Les noyaux somatiques de embryons du puceronMyzus persicae prirent la marque de la thymidine H³ 30 min après son injection dans l'hémocoele maternelle. L'absorption des molécules de cette substance à travers l'épithélium folliculaire et les membranes de l'embryon fut donc très rapide. Le marquage des métaphses s'est produit après 90 min. Dans les chromosomesX, l'incorporation fut nettement tardive.     

Urea cycle and purinolysis in the embryos and pregnant females of the teleost fish Poecilia reticulata]

The presence of a functional ornithine-urea cycle is evidenced in the embryos of the viviparous Teleost Poecilia reticulata. The activity of the cycle decreases during developmental period but persists in adult tissues. Purinolytic (uricolytic) pathway is another source of urea in both embryos and adults. The implications of these findings are briefly discussed in relation to the problems of ureogenic and ureosmotic phenomena in Teleostean Fishes.     

Triple cones found in retinas of 3 fish species

Summary Triple cones were found in the retinas of 3 species of fishes indigenous to the Woods Hole area. The function of these triple cones can not be deduced from the behavior patterns of these fishes.We wish to thank Kathleen French for her advice and criticism in the preparation of this paper.     

Über eine Synthese von Ecdyson-3H und Ecdysteron-3H aus Cholesterin-3H in geschnürten Abdomina vonMamestra brassicae-Raupen

Summary After application of cholesterol-³H in ligated abdomina of 5th larva stages of the caterpillarMamestra brassicae ecdyson-³H and ecdysteron-³H was demonstrated in the abdomina 6 days after injection. The results show that in this case the synthesis of the moulting hormones from cholesterol occurs without participation of the prothoracic glands.