Comparative immunochemical study of the serum proteins of Lacertilia (Reptilia)]

The immunochemical relationships of the serum proteins of Uromastix acanthinurus, Agama mutabilis, Oplurus cuvieri, O. quadrimaculatus, Chamaeleo chamaeleon, Chalcides ocellatus and Lacerta lepida were studied by means of immunoelectrophoresis with an antiserum anti-Uromastix successively absorbed. Homogeneity of the Iguania species was pointed out and they were found more closely related to the Scincid Chalcides ocellatus than to the Lacertid Lacerta lepida. Within the Iguania, the two Agamids are immunologically more closely related to the Chamaeleon than to the two Iguanids.     

Résorption intestinale de la ferritine chez deux espèces animales aux possibilités d'absorption protéique néonatale différentes

Summary The intestinal absorption of equine ferritin was studied in newborn rats and rabbits by means of electron microscopy and immunological tests.The absorption of ferritin begins by invagination of the plasma membrane, which forms vesicles and vacuoles in the brush border region. The ferritin moves downwards into the great supranuclear vacuole and then is taken up by the Golgi complex. The protein travels freely through the neighbouring cytoplasm and arrives into the dilated intercellular space. After passing through the basal membrane, the ferritin penetrates into the vessels.The intracellular course of ferritin is the same in both species and corresponds to that of other substances such as lipids.On the contrary, the immunological demonstration of this protein in peripheral blood is possible only in newborn rats; in young rabbits it disappears immediately after its arrival in the circulation.

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Nous exprimons notre reconnaissance au Chef du Centre de Microscopie Electronique, Monsieur A. Gautier, pour ses conseils et ses suggestions, et à Monsieur D. Anders pour sa collaboration technique. Les schémas ont été réalisés par Monsieur O. Jenni et nous l'en remercions vivement.Pour ce travail nons avons bénéficié d'une aide financière de la Maison Nestlé S. A. Vevey, à laquelle nous témoignons notre gratitude.     

Intranasal vaccination with a lentiviral vector protects against SARS-CoV-2 in preclinical animal models

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Comparative study of sexual cycles, oogenesis and spawning of two Soleidae, Solea lascaris (Risso, 1810) and Solea impar (Bennet, 1831), on the western coast of Brittany

Two sand sole species, Solea lascaris and Solea impar , are common on the western coast of Brittany, France. Their reproduction (oogenesis and spawning) has been studied by following the gonadosomatic index, histological changes in ovary development, and oocyte diameter distribution. Both species have a prolonged spawning season, from spring to late summer. Each mature female breeds twice during the spawning season: in May and July for 5. lascaris , and in early June and July for 5. impar. Throughout the spawning season, several oocyte batches undergo vitellogenesis and there is a continuous recruitment of immature or primary oocytes into vitellogenesis. The two species are thus serial synchronous spawners. This, together with oocyte atresia late in the season (especially noticeable in S. impar ) makes fecundity estimation difficult.     

Early interactions during the encounter of plants,aphids and arboviruses

Aphids infest many plants and cause damage by depriving them of nutrients and by transmitting many viral diseases. Aphid infestation and arbovirus transmission are controlled by establishment (or not) of a compatible reaction between the insects and the plants. This reaction is the result of defense reactions of the plant and counter-defense reactions of the parasite. Contrarily to plant-bacteria, plant-fungi and plant-herbivorous insects pathosystems, the plant-aphid pathosystem is understudied, although recent advances have begun to uncover some of its details. Especially the very early steps in plant-aphid interactions are hardly known. We here resume the present knowledge of these interactions. We discuss further how an aphid-transmitted plant virus that is transmitted during the first moments of the plant-aphid encounter, might help to study the very early plant aphid interactions.     

The effects of age and sex on the acute toxicity of two barbiturate anesthetics in rats]

The study of the acute toxicity of two barbiturics anaesthetics (pentobarbital and thiopental) shows the newborn period a higher susceptibility of the young rat, probably due to an immaturity of biotransformations enzymatic systems or to an increased blood-brain-barrier permeability.     

Streptococcus shiloi andStreptococcus difficile: Two new streptococcal species causing a meningoencephalitis in fish

The cellulolytic rumen bacteriumRuminococcus flavefaciens 17 was found to produce multiple xylanases ranging in apparent molecular weight from 55 to 200 kDa. A 55 kDa xylanase showed constitutive synthesis, but formation of the larger enzymes was increased in cultures grown with avicel, straw, or xylan, compared with cellobiose, as the energy source. At least six xylanases were detected in cultures grown with oat straw or oat xylan. Polyclonal antibodies were raised against the amino (A) or carboxy terminal (C) domains of the bifunctional XYNA product of the clonedR. flavefaciens xynA gene. Both antibody preparations recognized several xylanases larger than 80 kDa fromR. flavefaciens cells grown with avicel, straw, or xylan, indicating the production of multiple, antigenically related enzymes during growth on these substrates. Neither antibody preparation recognized the constitutive 55-kDa xylanase.