Analyse de populations d'isastrées bajociennes (Scléractiniaires jurassiques de France). Conséquences taxonomiques stratigraphiques et paléoécologiques

The present statistical study of two Bajocian populationsof Isastrea from eastern France uses different methods of measurement taking into account the colonial character. The results of the univariate and the multivariate analyses together with direct observation of qualitative characters show that only two species are present in the samples: Isastrea bernardiana and I.tenuistriata. A new synonymy is suggested for the Bajocian species. Genera such as Andemantastraea All. and Parisastraea All. correspond to the common variation of Isastrea. The taxonomic position of other Jurassic Isastrea is examined. It is probably possible to use extreme morphotypes as stratigraphic markers owing to an eventual anagenesis.A comparison between the two samples denotes that the variation range or the mean value of some quantitative characters (number, thickness of septa, dimension of corallites, trabecular density) contributes to the paleoecological interpretation.The present paper emphasizes the necessity ofwell-defined species based preferably on population study, for a reliable generic definition.     

Fortes différences des ADN mitochonclriaux de populations de Sardinella aurita de la mer Méditerranée et de l'Atlantique Est

Digestion by restriction enzymes has been carried out on polymerase chain reaction products of the mitochondrial DNA control region of round sardine (Sardinella aurita) samples coming from the Eastern Atlantic and the Mediterranean Sea. The results show i) that, though the habitat is continuous, there is no gene flow between the two basins where two genetically differentiated groups can be recognized, ii) that each basin is genetically homogeneous and, iii) that the haplotypic diversity in the Mediterranean is between two and three times smaller than that observed in the Atlantic. These results can hardly be explained by a recent colonization from the Eastern Atlantic. This suggests that, for S. aurita and some other species, the Mediterranean Sea is genetically little influenced by the Eastern Atlantic.     

Arthrite rhumato?de juvénile et HLA-B27.

Forty children with juvenile rheumatoid arthritis were studied to determine the frequency of the histocompatibility antigen HLA [human leukocyte antigen)-B27 in this disease and to characterize the arthropathy associated with this antigen. HLA-B27 was detected in four patients (10%). Its presence was associated in a statistically significant manner with sacroiliitis demonstrated radiologically and with a greater age at the time symptoms in the joints first appeared; this age was, on average, 10 years, compared with 6.29 years for the children without HLA-B27.     

Facteurs de limitation des populations d'Aphis fabae dans l'ouest de la France III. Répartition et incidence des différentes espèces d'Entomophthora dans les populations

Résumé Plusieurs espèces d'Entomophthora participent à la régulation des populations d'Aphis fabae Scop. sur féverole dans l'Ouest de la France. Les r?les respectifs de chaque espèce ont été évalués en 1971 et de 1973 à 1975. Entomophthora fresenii Nowak. est l'espèce qui se dissémine le plus rapidement et le plus complètement dans les parcelles, et qui est la plus agressive au niveau des colonies. Ces deux caractères en font l'agent pathogène dominant d'A. fabae dans l'Ouest, 3 années d'observations sur 4.Entomophthora aphidis Hoffman, bien que présent tous les ans n'est le pathogène le plus efficace qu'en 1973.Entomophthora thaxteriana Petch etEntomophthora planchoniana Cornu n'apparaissent pas chaque année et, lorsqu'ils sont présents, n'interviennent que pour une faible part dans le développement des mycoses. Des facteurs inhérents à l'agent pathogène (spécificité, caractères du cycle) ainsi que des facteurs écologiques (climatiques) sont évoqués pour expliquer la prédominance d'E. fresenii.

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Summary Several species ofEntomophthora take part in the natural control ofAphis fabae Scop. on field beans (Vicia faba) in the West of France. The respective importance of each species was assessed in 1971 and from 1973 to 1975. Entomophthora fresenii Nowak. is the species that most completely and quickly spreads in the fields, and the most efficient in the colonies. For both reasonsE. fresenii is the main pathogen ofA. fabae in the West of France 3 years over 4. AlthoughEntomophthora aphidis Hoffman occurs every year, this species was the most efficient pathogen in 1973 only.Entomophthora thaxteriana Petch just occurred in 1974 and 1975 and, these years, its contribution in the total sum of infected aphids was low.Entomophthora planchoniana Cornu appeared in 1975 only, very late in the season, which makes its pathogenicity difficult to assess. Factors inherent to the pathogen (specificity ofE. fresenii, nature of its cycle, dependence of the aggregation of aphids) and ecological factors such as response to climate variations, may at least to a great extent explain the predominance ofE. fresenii. All these factors must be studied for a good understanding of this species.

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Les 2 premiers mémoires de cette étude ont été publiés dans Entomophaga respectivement parRobert et al. (18, 1973, 61–75) etRabasse & Robert (20, 1975, 49–63)     

Espaces de représentation et psychopathologie

A subjective world can be conceptualized as a “representational space” — that is, as a universe displayed from memory, in which the subject “is sailing”. Recent cognitive theory provides some conceptual tools for describing such a space in a relevant way for clinical purposes. The construction of a representational space is based on mental representations: (a) analogical representations, which display a content in working memory; (b) symbolic representations, which code and link up analogical representations to form a represented world. The dynamics of representations and affects is ruled by a principle of unification of representational space. The topology of a representational space depends on objective and subjective constraints which cause some “folds” and limit the display of such a space. The interaction between an event and a subjective memory can be analyzed within this framework, so that the concepts of trauma and defence processes can be defined. Clinical syndromes are defensive configurations that tend to close the representational space.     

Syndrome de klinefelter et conseil génétique

Klinefelter’s syndrome is a common sex chromosomal aberration generally characterized by hypergonadotrophic hypogonadism and azoospermia. However, spermatogenesis impairment is variable and severe oligozoospermia can be found in some men, particularly those exhibiting a mosaic karyotype 47,XXY/ 46,XY. New reproductive technologies, such as intracytoplasmic sperm injection (ICSI), allow Klinefelter patients to have a progeny, even those who are azoospermic after testicular sperm recovery. The question therefore arises of whether or not there is a genetic risk for pregnancies from affected fathers. Sperm karyotyping, by in vitro penetration of zona-free hamster eggs or by fluorescence in-situ hybridization (FISH), is a method of choice for measuring aneuploidy rate in spermatozoa of patients carrying gonosomal abnormalities. A theoretical model would predict a high level of 24,XX and/or 24,XY disomic sperm cells in Klinefelter patients if 47,XXY spermatogonia were able to complete meiosis and achieve spermatogenesis. Interestingly, current observations show that the rate of abnormal spermatozoa in these patients is low, around 1–2%, which indicates that only 46,XY spermatogonia can produce mature sperm cells and that oligozoospermic Klinefelter patients probably carry a 47,XXY / 46,XY mosaicism, at least at the testicular level. However, this low but statistically significant level of disomic spermatozoa emphasizes the fact that their spermatogenesis occurs in a compromised environment which could increase the risk of meiotic errors. Therefore, the possible occurrence of autosomal aneuploidies in children born from Klinefelter fathers leads to the following recommendations: a) individual analysis by FISH of the sperm aneuploidy rate in each Klinefelter patient candidate for ICSI; b) proposal of fetal karyotyping after amniocentesis in pregnancies obtained by this technique.     

Une histoire de géométrie et de finesse (ou : comment parler de phylogénétique ?)

The development of phylogenetic methods since the beginning of the 1970s is analyzed through Armand de Ricqlès’ comment, in 1975, on the triumph of the spirit of geometry over the spirit of finesse. Cladistics was then compared to geometry (Hennig's congruence [i.e. congruent character-state trees]). However, the qualitative aspect of anatomy (spirit of finesse) warrants the quality of a taxon × character matrix so that minimal length trees were never devoid of finesse. Statistical approaches, especially maximum likelihood and Bayesian methods, with sophisticated mathematics (more rigorous geometry?), have reached a wide acceptance after years of debates hindered by polemics. The molecular trees based on these approaches are now dominating the phylogenetic literature, although these trees too include some ambiguity so that one can wonder: do evolutionary models belong to geometry or finesse?     

L' α-Glycérophosphate-déshydrogénase du moustique Culex pipiens: Génétique formelle,linkage et étude de populations

THE -CLYCEROPHOSPHATE-DEHYDROGENASE IN THE MOSOUITO CULEX PIPIENS: HEREDITY, LINKAGE AND POPULATION STUDIES. Culex pipiens -glycerophosphate-dehydrogenase is coded by an autosomal locus which is shown to have a demonstrable activity in nymphs just prior to imago emergence and in adults of any age and sex. The -Gpd locus has two codominant alleles, -Gpd ^1.00 and -Gpd ^1.30, and heterozygotes present three isozymes. The -Gpd locus is localized on the same chromosomes as the two linked esterase loci Est-2 and Est-1, at 37.05 and 44.88 cross-over units, respectively, of these loci. Population studies seem to indicate that the -Gpd locus has a low variability in Culex pipiens as in most other organisms.     

Techno-économie et signification culturelle de l’occupation moustérienne supérieure de Baume-Vallée (Haute-Loire)

The archaeological units of the Baume-Vallée rock shelter (Haute-Loire) in the South-East of the Massif Central, excavated by A. Laborde (from 1966 to 1973) then by J.-P. Raynal (from 1974 to 1996), have yielded abundant lithic assemblages attributed to the late Middle Paleolithic, characterized by a remarkable diversity of the raw materials used. The lithic industry of the upper units had previously been described as belonging to the Charentian facies lato sensu, then was attributed to the Ferrassie-type Mousterian. The technology and the techno-economic revision of its upper assemblage bring new information on the flaking mechanisms and the steps of the chaînes opératoires. These data tend to include this assemblage in the Levallois techno-complexes with scrappers often observed in late Middle Paleolithic of southeastern France.     

Ultrastructure de l'épithélium tégumentaire de Glossiphonia complanata (L.) (Hirudinée): cellules épithéliales et organes sensoriels de Bayer

Résumé Le tégument de Glossiphonia complanata comprend, outre les cellules épithéliales banales, de nombreux organes particuliers ou organes de Bayer, regroupés essentiellement sur la face dorsale de l'animal. Ils sont formés par une cellule apicale saillante enchassée dans une cellule musculaire en anneau.L'ensemble de ces formations est étudié du point de vue ultrastructural. Des cellules épithéliales partent des fibres nerveuses afférentes, sans doute vecteur des perceptions de stimuli mécaniques de pression au niveau du tégument; la réponse se faisant sans doute par la contraction de la cellule basale de chaque organe de Bayer, innervée par des fibres nerveuses efférentes, entrainant la saillie de la cellule apicale. Le hérissement de ces nombreuses papilles du tégument dorsal pourrait être un signal perçu par le partenaire sexuel, chez cette Hirudinée à fécondation hypodermique.

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Ultrastructure of the integumentary epithelium of Glossiphonia complanata (L.) (hirudinea): Epithelial cells and sensory organs of bayer

Summary The integument of Glossiphonia complanata, built up by epithelial cells, contains numerous particular organs (Bayer organs), mainly on the dorsal side of the animal. They consist of a protuberant apical cell, which is surrounded by a ring-shaped muscle cell. All the integumentary formations are studied from an ultrastructural point of view. From the epithelial cells issue afferent nerve fibres, considered as vectors of the perception of mechanical stimuli of pressure at the level of the integument; the response no doubt operating by the contraction of the basal muscle cell of each Bayer organ, innervated by efferent nerve fibres, bringing forth the protrusion of the apical cell. The erection of these numerous papillae of the dorsal integument might be a signal perceived by the sexual partner, fecundation occurring in this group of leeches under the integument.

     

Infrastructure superficielle de la vésicule vitelline et du sac péricardique de l'embryon de Poecilia reticulata (Poisson Téléostéen)

Résumé Le microscope électronique à balayage montre l'existence d'un réseau complexe de microcrêtes à la surface de la vésicule vitelline et du sac péricardique de l'embryon de Poecilia reticulata. Cette étude permet également de préciser la localisation, l'aspect et la répartition des «cellules à chlorure» et de proposer un schéma tridimensionel de l'organisation infrastructurale de la paroi de la vésicule vitelline. Un choc osmotique détermine rapidement un mouvement d'étalement des cellules épithéliales sur la surface apicale libre des «cellules à chlorure». La signification de ces résultats est discutée en rapport avec le problème de l'osmorégulation embryonnaire chez les Poissons, en particulier chez les Cyprinodontes vivipares de la famille des Poeciliidae.

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Ultrastructure of the yolk sac and pericardial sac surface in the embryo of the teleost Poecilia reticulata

Summary A complex network of microridges is revealed by scanning electron microscopical examination of the yolk sac and embryonic pericardial sac surface of Poecilia reticulata. This study also specifies the localization, aspect and distribution of the chloride cells. A tridimensional diagram of the ultrastructural organization of the yolk sac wall is suggested. Osmotic stress quickly induces an overlapping of adjacent epithelial cells on the free apical surface of the chloride cells. These findings are discussed in relation to the problem of embryonic osmoregulation in fishes and especially in viviparous Poeciliids.

Nous exprimons notre gratitude à Mme Neumann, Directeur du Laboratoire de Micropaléontologie de l'Université Paris VI, qui nous a permis d'utiliser le microscope électronique à balayage qui a servi à cette étude. Nos remerciements s'adressent aussi à Melle Aubry et à M. Saussé pour leur concours technique. — Les observations en microscopie électronique en transmission ont été effectuées au Laboratoire de Microscopie électronique appliquée à la Biologie du C.N.R.S.     

Evolution du polymorphisme enzymatique dans des populations expérimentales de Drosophila melanogaster III. Déséquilibre de linkage entre les locus Adh et α-Gpdh

Evolution of enzyme polymorphism in experimental populations of Drosophila melanogaster III. Linkage disequilibrium between alleles of the Adh and -Gpdh loci — The evolution of gametic frequencies and linkage disequilibria between alleles of the Adh and -Gpdh-loci was followed in two experimental populations of Drosophila melanogaster maintained at different temperatures. The results observed were compared with those expected on the basis of theoretical models of gametic selection. Gametic fitness values were estimated from the analysis of the productivity of the different homozygous genotypes.Our experimental results indicate that the selection favours an association between the alleles Adh-F and -Gpdh-S, but it is impossible to generate and/or maintain a stable linkage disequilibrium between the two alleles.     

Chromosomes et hétérochromosomes de ténébrionidés

Sans résumé Avec 81 figures dans le texte