ACETYLCHOLINESTERASE DU MUSCLE, DE LA MOELLE EPINIERE ET DU CERVEAU DE GYMNOTE

Résumé— Dans le but d'étudier la localisation cytologique de I'AChE dans divers tissus de Gymnote, nous avons préparé un antisérum anti-AChE en utilisant une préparation commerciale partiellement purifiée, contenant une forme globulaire de l'AChE G _p. Cet antisérum réagit dans le test de double diffusion avec l'enzyme purifié G _p, mais également avec la forme globulaire spontanée G _b, ainsi qu'avec les trois espèces 'natives' asymétriques A , C et D . Nous avons mis en évidence l'existence de ces quatres formes G _b, A , C et D dans des extraits de cerveau, de moelle épinière et de muscle de Gymnote. La forme globulaire G _b est particulièrement abondante dans la moelle épinière et à un moindre degré, dans le cerveau. La distribution des espèes est identique dans le muscle et l'organe électrique. Grâce à notre antisérum, nous avom Iocalisé par immunofluorescence indirecte l'AChE dans les terminaisons nerveuses sur le muscle, dans le cytoplasme de certains neurones situés dans le centre moteur de la décharge (moelle épinière) et au voisinage du noyau central de la décharge (cerveau).     

METABOLISME DU CALCIUM ET LIBERATION DE L''ACETYLCHOLINE DANS L''ORGANE ELECTRIQUE DE LA TORPILLE

Abstract— Calcium metabolism was studied in the electric organ of Torpedo , at rest and after electrical stimulation, in vivo and in vitro , by measuring total calcium and using ⁴⁵Ca. Seasonal variations in the calcium metabolism were observed, summer animals being richer in the ion than winter ones. When the tissue was incubated in high calcium concentrations, complete exchange was obtained between cellular calcium and that of the external medium. In the presence of low concentrations, the tissue retained its calcium which, in this case, was poorly exchanged. Stimulation was accompanied by a net increase of cellular calcium and by acceleration of its exchange with that of extracellular space. This entry of calcium seems to involve mainly the presynaptic nerve endings, since it is also observed when transmission was blocked by curare which acts at the level of the postsynaptic electroplaques. Calcium may also influence the intracellular repartition of the transmitter. As a matter of fact, the presynaptic entry of calcium is accompanied by diminution of 'bound' ACh (vesicular ACh). When the tissue was incubated in a solution devoid of calcium, especially if EDTA was added, the electrical response disappeared; then 'free' ACh which is the immediately available compartment, decreased but its turnover rose. 'Bound' and 'free' ACh were also measured under various conditions of homogenization and the results discussed. It is concluded that extracellular calcium is required for the maintenance of the immediately available compartment of ACh.     

ÉTUDE AU LABORATOIRE DE LA RECHERCHE DU SITE DE TISSAGE DU COCON PAR LES LARVES DE CHRYSOPA PERLA (L.) (NEUROPTERA,CHRYSOPIDAE)

Résumé Les larves de Chrysopa perla lorsqu'elles sont prêtes à tisser leur cocon manifestent une tendance à descendre de leur support, recherchant secondairement untsite obscur et qui assure le contact. Lorsque le milieu est sect et meuble, elles s'enfouissent à une profondeur qui n'excède pas 20 mm dans la sciure. Les larves destinées à entrer en diapause s'enterrent plus profondément que celles qui ont un développement rapide continu. L'humidité excessive est un facteur répulsif énergique interdisant le plus souvent le tissage d'un cocon étanche. Lorsque le milieu ne permet pas l'enfouissement, les larves tissent successivement au contact les unes des autres, provoquant ainsi le regroupement des cocons.

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Summary The larvae of Ch. perla tended to leave their supports and look for a dark, thigmotactic place when ready to spin their cocoons (Table III). Darkness is not essential for spinning, successful pupation behaviour or for a low prenymphal mortality, under the light-intensity conditions used (3,000 lux). Under extremely wet conditions, the larvae did not easily find a place to spin their cocoons and may in fact return to their original support. In such conditions, the active larval stage for searching a suitable spinning place increased, the larva may die before a cocoon has been spun or an abnormal rough, porous, yellow cocoon may be made.Ideally a loose, dry substratum was chosen to spin the cocoon; the light substratum (sawdust and vermiculite) was always chosen in preference to the heavy one (earth and sand) and a dry substratum rather than a wet one (Table IV). In the light substratum, pupation took place in the upper 20 mm. In the heavy substratum, cocoons were spun on the surface and were adjacent to each other (Fig. 1) to allow support for the external threads. In both cases, substrate particles enclosed the cocoons.When the larvae were subjected to diapausing conditions by a short-day photoperiod, the mean weight of the cocoon was larger (14.21±1.83 mg) than if development was rapid and continuous (13.00±1.84 mg). Larvae which have been induced into diapause were found deeper in the sawdust than those which had not (Figs 2 and 3); but the difference was too small to be used as a method of separating the two populations.

     

ETUDE ONTOGENETIQUE DE L'ORGANE SENSORIEL DU MUSCLE CRUCIFORME DES TELLINACEA

The closed cruciform muscle sense organ of Donax trunculus hasa similar origin to the open one of Scrobicularia plana. Bothdifferentiate as ectodermal pits before the cruciform muscleitself, which is issued from their wall. The sense organ ofDonax is closed immediately after the invagination of the pitand its closure is independent of the differentiation of theventral expansion which characterizes the closed sense organand of the canal which characterizes the open one. (Received 8 August 1983;     

ÉTUDE DE LA PHÉROMONE SEXUELLE DE LA TEIGNE DU POIREAU ACROLEPIOPSIS ASSECTELLA

Le composant principal de la sécrétion phéromonale produite parla femelle vierge de Acrolepiopsis (Acrolepia) assectella Zell. a été identifié par chromatographie en phase gazeuse, spectrométrie de masse, tests électrophysiologiques et olfactométrie comme étant l'hexadécène-11Z al (Z₁₁HDal). Ce composé est le plus actif en électrophysiologie parmi tous les autres acétates, alcools, aldéhydes et formiates, de C₁₂ à C₁₈, éprouvés sur l'antenne du mâle et il est capable de produire chez ce dernier une séquence comportementale sexuelle complète en olfactomètre à tube. Dans la nature, des capsules en caoutchouc chargées à 1 mg de Z₁₁HDal (plus 10% d'antioxydant) attirent sélectivement les mâles et sont compétitives avec des femelles vierges. L'isomère E (E ₁₁HDal) est environ 10⁴ fois moins actif tandis que l'acétoxy-1 hexadécène-11Z (Z₁₁HDA) et l'hexadécène-11Z ol-1 (Z₁₁HDol) inhibent le pouvoir attractif du Z₁₁HDal.

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Summary The main component of the sex pheromone secretion produced by virgin females of A. assectella has been identified as Z-11 hexadecenal (Z₁₁HDal) by GC analysis and mass spectrometry, EAG tests, and behavioural assays. Z₁₁HDal elicited the highest EAG response of all C₁₂ to C₁₈ acetates, aldehydes, formates and alcohols tested, and induced a typical sequence of male sexual behavioural responses in olfactometer tests. In the field, traps baited with 1 mg Z₁₁HDal on rubber septa (with 10% antioxidant) attracted male moths selectively and were competitive with virgin females. The E isomer (E ₁₁HDal) was 10⁴ times less attractive, whereas Z11-hexadecenyl acetate and Z11-hexadecen-1-ol, in admixture with Z₁₁HDal strongly inhibited male responses.

     

BIOSYNTHESE DES GLYCOPROTEINES CEREBRALES: ETUDE DE L''ACTIVITE MANNOSYL-TRANSFERASE PARTICULEE DU CERVEAU

In the brain, mannosyl-transferase activity, from GDP-mannose to glycoproteins, is localized in a subcellular fraction including microsomes and synaptosome fragments. This enzymic complex has two maxima of activity, at pH 5·9 and 7·4. It is activated by pre-incubation at supraoptimal temperatures which modifies the enzyme-substrate environment, and is activated also by the detergent Triton X-100 and by the cations Mn²⁺ and Mg²⁺, but is inhibited by nucleoside-diphosphates, GTP and βγ-methylene GTP. Cycloheximide has no effect on transglycosylation, but puromycin reduces the mannosyl-transferase activity. This is interpreted as good evidence for the importance of attachment of the polypeptide chain to polysomes during transglycosylation.     

ETUDE QUANTITATIVE PAR RADIOAUTOGRAPHIE AU MICROSCOPE ELECTRONIQUE DE L'UTILISATION DE LA DL-LEUCINE-3H PAR LES CELLULES DE L'HYPOPHYSE DU CANARD EN CULTURE ORGANOTYPIQE

The synthesis, intracellular transport, storing, and excretion of proteins by duck hypophyseal cells in organ culture were studied with tritiated DL-leucine and high resolution radioautography (pulse-labeling experiments). Quantitative study of the radioautographs allowed a determination of the relative proportions of cytoplasmic radioactivity located in each cellular compartment (ergastoplasm, Golgi apparatus, and protein granules) as well as the variations in these proportions as a function of time. The number of labeled protein granules as opposed to the total number of granules in the cell was also determined (RSg). These data were separately analyzed for the two types of cells present in the explants: prolactin cells and "MSH" cells. The synthetic process follows a course common to both cell types, each of which is distinguished by its particular modalities. The labeled proteins, synthesized within several minutes in the ergastoplasm, are concentrated in the Golgi zone within 30 min. They then migrate out of this area, the emptying of which is accomplished in about 4 hr. These proteins become equally distributed between the protein granules, on the one hand, and the cytoplasm ("sedentary" proteins), on the other. The RSg reaches its maximum when the Golgi zone is emptied, but this figure remains very low (3%). The RSg then decreases slowly (1% in 40 hr). It is concluded that hypophyseal cells are able to store protein in their granules and that their processes of synthesis and excretion are not continuous. The prolactin cells differ from the "MSH" cells in that they have a slower migration of newly synthesized proteins, and these proteins pass via the dilated ergastoplasmic cisterns in which they may possibly be stored.     

INFLUENCE DE LA PRESENCE DU MÂLE,DE LA LUMIERE ET DU SUBSTRAT DE PONTE SUR LE DEPOT DES ŒUFS CHEZ HYDRELLIA GRISEOLA (DIPTÈRE,EPHYDRIDAE)

Résumé L'activité de ponte d'Hydrellia griseola Fall. est étudiée dans différentes conditions expérimentales. Lorsqu'elles sont accouplées et qu'elles bénéficient d'un régime photopériodique, les femelles déposent leurs ufs sur une feuille d'Orge (Hordeum vulgare) exclusivement pendant la phase lumineuse.La ponte quotidienne débute le 3ème jour, augmente jusqu'au 5ème et diminue ensuite. L'activité de ponte n'est donc pas constante au cours du temps, mais aucun cycle n'apparaît.Quand les femelles sont vierges, la ponte est plus faible mais son évolution au cours du temps est la même.A l'obscurité continue la période préreproductrice s'allonge et l'activité de ponte est ralentie, tout en conservant pendant les premiers jours le rythme quotidien observé chez les femelles bénéficiant d'une photopériode.Enfin, l'absence momentanée de la plante-hôte pendant les premiers jours de la vie reproductrice arrête momentanément l'activité de ponte; celle-ci reprend très fortement le jour de la réintroduction du végétal; puis, les jours suivants, elle se stabilise au niveau de celle des témoins, l'ensemble se traduisant par un déficit dans le nombre des ufs pondus quand la plante-hôte est absente plus de 48 h.

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Summary The egg-laying activity of Hydrellia griseola was studied. Mated females kept in an artificial photoperiod laid eggs on barley leaves during the light period only. Oviposition began when adults were 3 days old, and egg numbers laid rose to a peak on the 5th day, when it gradually declined. Egg laying was not constant. Virgin females shared the same trends, with oviposition occurring on the 3th day but less eggs were laid.When females were kept in continuous darkness with a male and a host plant for egg laying the preoviposition period was longer and egg laying was reduced during the first few days.The temporary removal of the host plant during the first few days temporarily arrests egg laying, which began again, vigorously, when the host plant was returned. Removal of the host plant for more than 48 h caused a reduction in the number of eggs laid.

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Je dédie ce travail à la mémoire du Professeur J. R. le Berre, en hommage respectueux et ému.     

LOCALISATION MITOCHONDRIALE D'ENZYMES LIEES AU METABOLISME DU GLYCOGENE DANS LE SPERMATOZOIDE DE L'ESCARGOT

The mitochondrial derivative of the sperm cell of the Gastropod Helix is endowed with a compartment loaded with glycogen (Personne et André, 1964). The aim of this work is to establish whether this mitochondrial glycogen is synthesized in the mitochondrial derivative itself or elsewhere in the cell. For this purpose, living sperm were first incubated in a medium containing glucose 1-phosphate, then fixed, sectioned, and stained specifically for polysaccharides by the phosphotungstic acid technique or the periodic acid-thiosemicarbazide-silver proteinate technique. Comparison with controls shows that a synthesis of glycogen occurred during the time of incubation. It can be inferred from this result that an amylophosphorylase system controlling the metabolism of polysaccharides is present in the mitochondrial derivative itself. Results obtained with the iodine technique indicate that the original glycogen molecules are elongated during the experiment. It seems probable that the amylophosphorylase system demonstrated here accounts for at least a part of the proteinaceous coat morphologically detectable around each individual glycogen particle.     

INFLUENCE DU SUPERPARASITISME SUR LA DURÉE DU DÉVELOPPEMENT LARVAIRE ET LE POIDS DU PARASITOÏDE LIXOPHAGA DIATRAEAEÉLEVÉ DANS UN HÔTE DE SUBSTITUTION GALLERIA MELLONELLA

Résumé G. mellonella infestée au dernier stade larvaire avec 1, 2, 3 ou 5 planidia/hôte (ph/H) produit 1 à 5 pupes/hôte (pu/H). La mortalité des chenilles augmente avec le nombre de pl/H. Le poids des pupes et décroît avec un nombre croissant de pu/H (18,2 à 12,9 mg pour les et 12,5 à 9,7 mg pour les ). Le développement larvaire dure 8,7 j. chez les et 8,3 chez les ; il est peu affecté par le superparasitisme. Avec 1, 2, 3 et 5 pl/H nous obtenons 0,84–1,61–2,17 et 3,43 pu/H et 0,81–1,48–2,10 et 3,11 imagos/H. L'optimum est de 3 pl/H ou 1 à 2=pl/H pour obtenir des parasitoïdes plus lourds.

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Summary The influence of superparasitism on larval and pupal development is investigated. Last-larval instar G. mellonella (200±5 mg) were infected with 1, 2, 3 or 5 planidia/host (pl/H) producing 1 to 5 pupae per host (pu/H). Host mortality (8.6–8.3–14.3 and 22.2%) increased with the number of planidia. The planidia may transmit a bacteriosis. Pupal weight ( and ) decreased as number of pu/H increased. pupae were heavier than ones: 12.9 to 18.2 mg for against 9.7 to 12.5 mg for . Larval development lasted slightly longer for (8.7 d.) than for (8.3 d.), and its duration was little affected by superparasitism. 1, 2, 3 or 5 pl/H yielded 0.84–1.61–2.17 and 3.43 pu/H and 0.81–1.48–2.10 and 3.11 adults/H. An optimum was obtained with 3 planidia of L. diatraeae on G. mellonella or 1 to 2 to obtain heavier parasitoids.

     

VARIATIONS AU COURS DES DIX PREMIERS JOURS DE LA VIE POSTNATALE DE L''INCORPORATION IN-VIVO DE LA L-[3H]LEUCINE DANS LES PROTEINES DU CERVELET DU RAT NORMAL, HYPO- ET HYPERTHYROIDIEN

The incorporation of L-[³H]leucine into the proteins of rat cerebellum and cerebrum was measured 30min after an intravenous injection of the labelled amino acid. In normal rats. both RSA and the relative RSA of the proteins of the cerebellum and the cerebrum, varied greatly from one day to another during the first ten days of postnatal life. These variations showed a maximum of both the RSA and the relative RSA of the proteins on the 7th day, and 2 minima on the 3rd and 16th day. In hypothyroid animals, both the RSA and the relative RSA of the proteins of the cerebellum and the cerebrum were generally lower than in normal animals. Both showed a maximum at 7 days and a minimum at 3 days. In hyperthyroid animals, both the RSA and the relative RSA of the proteins of the cerebellum were significantly higher than those of normal animals. Both showed 2 minima at 2 and 5 days. In the hypothyroid animals as in the normal, protein synthesis was higher in the second postnatal week than during the first. On the other hand, in the hyperthyroid animals, protein synthesis was greater during the first postnatal week than during the second. The changes in both the RSA and the relative RSA values of the proteins of the cerebellum are discussed as a function of both growth and cellular proliferation. Hyperthyroidism advances these two processes without changing the period that separates them. On the other hand, hypothyroidism changes this period and causes a change in the development of these processes.