Purification de l'alcool deshydrogénase de tomate par chromatographie d'affinité

Tomato alcohol dehydrogenase has been purified 99-fold by affinity chromatography on Blue Sepharose CL-6B with 37% yield. The enzyme so obtained is homogenous in polyacrylamide gel electrophoresis. By adding 20% glycerol to the extraction and purification buffers, an enzyme is obtained which is stable for several months at 4°. The molecular weight values determined by gel filtration (Sephadex G 200) and polyacrylamide gradient gel electrophoresis on one hand and by polyacrylamide gel electrophoresis in sodium dodecyl sulfate on the other, show that the enzyme exists in dimeric form.     

Action de l'ecdystérone sur l'apolysis et l'ecdysis de divers crustacés isopodes

Ecdysterone acts differently according to the period of the moulting cycle when it is applied. In period C it induces apolysis, while at the beginning of apolysis it delays ecdysis. Experiments show that the exoskeleton cannot be rejected in the presence of ecdysterone. The possibility of stopping exuviation or ecdysis with ecdysterone seems to prove that this phenomenon is controlled by a particular factor called the factor of exuviation or the ecdysis factor. Ecdysterone would control only the release of this specific factor but would not prevent its action.     

Activité cytokinine de dérivés acylés,alkylés,acyl-alkylés de l'adénine et d'isost`eres azotés de la γ,γ-diméthylallyladénine

The cytokinin activities of various 6-acylaminopurines, 6-alkylaminopurines, 6-acylamino-9-benzyl-purines as well as a series of isosteric-nitrogen derivatives of N⁶-(γ, γ-dimethylallyl)adenine (I⁶Ade) have been tested using the tobacco pith and the pea bud bioassays. The interactions between active, slightly active and inactive compounds have been studied with the last assay. Acylation decreases the biological activity; e.g., N⁶-benzoyl and N⁶-furoyladenines are less active than Na⁶-benzyladenine and kinetin. Substitution at the 9-position reduces (tobacco-pith assay) or suppresses (pea-bud assay) the phytohormonal activity of otherwise active 6-acylaminopurines. In isosteric derivatives, maximum activity occurs when the side chain has the same length as in 1⁶Ade. After the analysis of interactions between more or less active compounds, it is suggested that the differences in cytokinin activity could be related to unequal affinities for a hypothetical receptor site.     

Structure d'adhérencedes grains de pollen en tétrade du genre Classopollis PFLUG, 1953, de l'Hettangien de Saint-Fromont,Manche (France)

Palynological inventory of Saint-Fromont pit 0815 (Manche, France) related to Hettangian seems to show the conspecificity of Classopollis chateaunoviReyre, 1970, Classopollis kieseriReyre, 1970 and Classopollis harisiiMuir & Van Konijnenburg-Van Cittert, 1970. SEM pictures exibit some sculptural elements interpreted as structural attachments of grains in tetrad and compared to those of genus DicheiropollisTrevisan, 1971.     

Structure cristalline d'une deuxième forme de mélézitose monohydrate. Effet de l'environnement sur la géométrie d'un oligosaccharide

Melezitose [O-α-d-glucopyranosyl-(1→3)-β-d-fructofuranosyl α-d-glucopyranoside] monohydrate crystallizes in two polymorphic forms (I and II). The structure of form II, studied by X-ray crystallography, shows an orthorhombic cell having a 7.135 (4), b 15.362 (8), c 19.134 (8) Å, space group P2₁2₁2₁, and Z 4. The structure, solved by direct methods, was refined to a final value of R 0.045. The molecule of form II seems to be more constrained by its crystalline environment than that of form I. These constraints imply not only little variations in glycosidic bonds, but also a change of conformation for the furanose ring, and a perceptible deformation of the sucrose pyranose ring. This study gives an example of estimation of oligosaccharide molecular-flexibility.     

Nanisme écologique de deux espèces d'échinides irréguliers dans l'Hauterivien de la région de Castellane (Alpes-de-Haute-Provence)

Three species of irregular see-urchins form the settlement of a marly level (lower Hauterivian) of the Castellane area. Two of them are strongly smaller than the norm. Their stunting is prouved by ontogenic, mecanical, sedimentological and ecological arguments. The ecological grounds of stunting are discussed.     

Découverte de microfaunes de l'Albienmoyen et supérieur dans la vallée de Joux (Jura Vaudois,Suisse)

The discovery of Foraminifera and Ostracodesin the dark green, sandy-glauconitic marl clay in the Joux Valley (in the Vaudois Jura) suggests to date these sediments Middle and Upper Albian. The Ostracode associations are similar to those found in the Paris Basin, but different from those which characterize the subalpine region.     

Trace nouvelle de locomotion de Chélonienet figures d'émersion associées dans les calcaires lithographiques de Cerin (Kimméridgien supérieur,Ain, France)

The first tetrapod Vertebrate track discovered in the late Kimmeridgian lithographic limestones of Cerin (Ain-France), is descrbed as a new ichnospecies, named Chelonichnium cerinense. The characteristics of the track, which is about 7 m long, suggest that it was made by a large Chelonian, but none of the fossil turtles known so far from Cerin is likely to be the author of these footprints. The ground on which the animal walked was apparently very wet, superficially soft, and sloping. Moreover, this track is associated to soft sediment slides, confirming emersion and slope. The depositional environment is interpreted as a platform located behind a «ribbon of islands. This irregular surface was at times emerged and terrestrial tetrapods could then leave tracks on the superficial layer.     

Modalités d'installation et d'évolutiondes Harpocératinés (ammonitina A) au Domérien inférieur dans le sud-Ouest de l'Europe (France,Portugal)

In Mesogea, the Harpoceratinae were known asearly as the end of the Lower Carixian. They later reached the sub-boreal province through the Alps or the South of the Iberic Peninsula. The analysis of the populations met in four crosssections of the Lower Domerian (Causses, Mâconnais, Franche-Comté, Portugal) showed the settling down of the Protogrammoceras isseli group that set up and evoluated in a similar way in the different areas in spite of a certain originality.On the one hand, it gave the cladogenetic groupP. monestieri-nitescens by diminution of the ribing density, strengthening of the ribs and simplification of the suture.On the other hand, a slower evolution give, near the end of the Stokesi zone, P. normanianum in the Paris Basin and in Burgundy, and P. lusitanicum in Portugal. At the same time, a new invader, P. celebratum, arrived in the Causses (and in Portugal).     

Obtention de lignées permanentes d'hémocytes de blatte. Caractéristiques physiologiques et ultrastructurales

Two new cell lines were established from larval and adult cockroach haemolymph. The cells show typical characteristics of plasmatocytes, but under different conditions of cultivation, they modulate from small dividing cells (prohaemocytes) to large storing cells (granulocytes, adipohaemocytes etc.). Consequently, the very confusing haemocyte nomenclature must be reconsidered taking into account the cell physiology. Biochemical analysis of the metabolized culture medium established bacteriolytic activity and chitinase secretion (two enzymes). Moreover, in the same medium we found a macromolecular factor inducing spermatogenesis in cultured germinal cysts of the Cynthia silkworm. All these characteristics of in vitro haemocytes are discussed to explain the involvement of blood cells in insect physiology and especially in immunity, gametogenesis, and ecdysis.     

Cycles embryonnaires et sécrétion de la cuticule chez l'embryon de blatte, Blabera craniifer

Cuticle deposition has been studied with the electron microscope in cockroach embryos (Blabera craniifer) during normal incubation in situ and in culture in vitro, in the absence or presence of inokosterone (a phytoecdysone).Two cuticles are deposited successively during embryonic life, respectively between stages 11 and 17, and stage 21 and 24 hr after hatching. The occurrence of two embryonic cycles is thus demonstrated, the first ending at stage 17 without exuviation since there is no old cuticle to be shed, the second one at hatching.In embryos explanted at stage 17 and cultured in vitro, the formation of cuticle 2 occurred at the same rate as in situ. The addition of inokosterone (50 μg/ml) to the medium resulted in the early onset of cuticle deposition (in 3 days as compared with 15 days in situ) in legs previously cut at the base of the tarsus. Cuticle 2 was completed within 9 days after explantation (as compared with about 20 days elapsing in the normal embryo between stage 17 and the completion of cuticle 2). Unsectioned appendages were insensitive to the hormone.Regeneration of sectioned legs, which occurred normally n vitro in non-treated embryos, was completely inhibited in the presence of inokosterone, presumably because the hormone caused early immobilization of cells through accelerated cuticle formation.Results suggest that embryonic cycles are controlled by the same hormonal mechanism as larval cycles.     

Utilisation de lois de la mécanique pour l'Estimationde la vitesse de locomotion des Vertébrés tétrapodes du passé

Two computation methods are explained; theirobject is the estimation of the velocity of animals which are known by their footprints, and in the case of the first method, by their skeletons as well.The first method is based on the compound pendulum theory, because during the slow walking gait, the motion of the leg is similar to the oscillation of a pendulum, for the computation of the velocity (v), are considered: moment of inertia (I), radius of gyration (P) and period (T), time in seconds to cover one stride (E) in the case the maximum angle of divarication (δ) of the leg with the vertical is ≤20°. A comparison with the formula of Alexander (1976) is discussed.The second method concerns saltator animals. It is based on the fondamental laws of dynamics. With the length of the jump (E) it is possible to estimate the velocity of the trackmaker (v) and the height of the jump (K). For the vertebrates the angle of the trajectory with the horizontal plan (α) is between 20 and 45°. Thus, the result of this method is an interval of estimation in which the velocity is included.These methods do not give precise results. But these approximations supply valid informations on the velocity of extinct or living animals and can lead to the estimation of their maximum speed if the parameters E, T, vary. The problem of the errors is also discussed. It is shown that the errors in estimating the parameters have a no significant influence on the results.     

Relation métabolique entre l'arginine et l'acide γ-aminobutyrique dans le fruit de Castanea sativa: étude préliminaire de l'arginase

Analysis of the free amino acid pool in the chestnut fruit (Castanea sativa) shows that it is high in γ-aminobutyric acid. A metabolic connection between arginine and γ-aminobutyric acid is evident. Three enzymatic activities are involved: L-arginine ureohydrolase, L-ornithine 2-oxo-acid aminotransferase and L-glutamate carboxylyase.     

Analyse biostratigraphique et paléontologique de l'Albien marin d'Estremadura (Portugal)

The marine Albain from Estremadura is splited up into four Orbitolinidae zones, adjusted to biostratigraphic scales from mesogean province: zone with Orbitolina (Mesorbitolina) minuta (lower to middle Albian); zone with Neorbitolinopsis conulus (base of upper Albian); zone with Orbitolina (Orbitolina) concava (top of upper Albian) and zone with Orbitolina (Orbitolina) duranddelgai (Vraconian). The vertical extension of the main fossils is replaced in the framework of these zones. The most interesting species for biostratigraphy, paleoecology or taxinomy are summarily described.     

Les vertébrés dévoniens de l'Iran central I: Dipneustes

The dipnoan dental plates discovered in the Frasnian of the Kerman region (Central Iran) are referred to the genera Rhinodipterus, ? Dipterus and ? Chirodipterus. The new taxon Iranorhynchus seyedemamii n. g., n. sp. is erected for a peculiar lower jaw with an elongate, spatula-shaped symphysial region, and with all the ventral and lateral dermal bones fused into a continuous exoskeleton. Furthermore, this lower jaw possesses a well-developed system of symphysial tubuli which is related to the bottle-shaped cavities of the exoskeleton (pore-canal system). A snout fragment from a large dipnoan is provisionnally referred to a rhynchodipterid.     

Révision de l'ichnogenre Coprulus Richter & Richter, 1939, et description de quelques nouvelles espèces du Jurassique supérieur

Coprulus, described by R. Richter & E. Richter (1939a) is very abundant in the Oxfordian marls and muddy limestones of the French Jura Mountains. These small cylindrical calcareous bodies are characterised by longitudinal grooves. They have been often found in washings but are also visible in thin sections. Coprulus is rarely mentioned by micropaleontologists but its stratigraphical and geographical range is certainly very extended. Often considered as Problematica, this trace fossil has been differently interpreted. This work confirms and specifies the results of F. Gramann (1966): Coprulus represents a fecal pellet of a deposit-feeder mollusc (Nuculidae?). Three new ichnospecies are described herein and the ichnogenus Coprulus is compared with Bactryllium, Coptocampylodon and Tomaculum.