Vagococcus teuberi sp. nov., isolated from the Malian artisanal sour milk fènè

Ten bacterial isolates belonging to the genus Vagococcus were obtained from Malian sour milk fènè produced from spontaneously fermented cow milk. However, these isolates could not be assigned to a species upon initial comparative 16S rRNA gene sequence analysis and were therefore further characterized. Rep-PCR fingerprinting of the isolates yielded four strain clusters represented by strains CG-21^T (=DSM 21459^T), 24CA, CM21 and 9H. Sequence identity of the 16S rRNA gene of DSM 21459^T to its closest relative species Vagococcus penaei was 97.9%. Among the four rep strain clusters, DSM 21459^T and 24CA shared highest 16S rRNA gene sequence identity of 99.6% while CM21 and 9H shared 98.6–98.8% with DSM 21459^T and V. penaei CD276^T. DSM 21459^T and 24CA were thus subjected to a polyphasic typing approach. The genome of DSM 21459^T featured a G + C content of 34.1 mol% for a 2.17-bp chromosome and a 15-kbp plasmid. Average nucleotide identity (ANI) of DSM 21459^T to Vagococcus fluvialis bH819, V. penaei CD276^T were 72.88%, 72.63%, respectively. DNA–DNA hybridization (DDH) similarities of strain DSM 21459^T to other Vagococcus species were <42.0%. ANI and DDH findings strongly supported the 16S rRNA gene phylogenetic tree delineations. The fatty acid patterns of DSM 21459^T was palmitic acid (C _16:0, 24.5%), oleic acid (C _18:1-ω9c, 32.8%), stearic acid (C _18:0, 18.9%). General physiological characterization of DSM 21459^T and 24CA were consistent with those of the genus Vagococcus. Strain DSM 21459^T and further strains are therefore considered to belong to a novel species, for which the nomenclature Vagococcus teuberi sp. nov. is proposed. The type strain is named CG-21^T (=DSM 21459^T and LMG 24695^T).     

Spécificité des hyphomycètes entomopathogènes pour les larves de lepidoptèresNoctuidae

Résumé L'étude de la sensibilité des 4 espèces de noctuelles,Mamestra brassicae L.,Spodoptera littoralis Boisduval,Spodoptera frugiperda Smith etScotia ipsilon Hübner, aux hyphomycètes a été conduite avec 10 souches dePaecilomyces fumoro-roseus (Wize) Brown & Smith, 6 deNomuraea rileyi (Farlow) Samson, 1 deBeauveria bassiana (Bals.) Vuill. et 1 deMetarhizium anisopliae (Metsch.) Sor. Les chenilles nouvelles-nées agées de moins de 16 h ont été exposées pendant 24 h sur des rondelles de feuilles contaminées par aspersion des inoculums, puis élevées individuellement à 25±1°C. A la dose de 3.10⁵ conidiospores/cm², l'activité pathogène des germes sur les chenilles varie dans de larges proportions suivant l'espèce-h?te et suivant l'isolat considérés. L'espèce la plus sensible à la plupart des souches estM. brassicae et la plus résistanteS. littoralis. Les germes les plus performants présentent des temps létaux 50% compris entre 2 et 3,5 j (à la dose de 3.10⁵ spores/cm²) et des doses létales 50% de 10³ à 10⁴ conidiospores/cm² (mortalités cumulées le 6e j après traitement); ce sont les isolats:P. fumoso-roseus n^o 13, 32, 39, 40 et 45 pourM. brassicae, N. rileyi n^o 5 pourS. littoralis; P. fumoso-roseus n^o 32 pourS. frugiperda etM. anisopliae n^o 139 pourS. ipsilon. La virulence élevée du pathotypeN. rileyi n^o 5 pourS. littoralis et son agressivité à l'égard des 3 autres noctuelles, confirment l'intérêt de cet hyphomycète en dehors de son aire d'origine (Sud-Est des Etats-Unis). Par ailleurs, les aptitudes des souches européennes deP. fumoso-roseus montrent que cette espèce présente des potentialités pour la lutte biologique contre divers noctuides.

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Summary Bioassays were carried out on 1st instar larvae to determine the relative susceptibility of 4 noctuid species,Mamestra brassicae L.,Spodoptera littoralis Boisduval,Spodoptera exigua Smith andScotia ipsilon Hübner to 10Paecilomyces fumoso-roseus, 6Nomuraea rileyi, 1Metarhizium anisopliae and 1Beauveria bassiana isolates. Neonate larvae, 2 to 16 h old, were exposed for 24 h to leaf pieces treated with conidial suspensions of each fungal strain and then transferred to untreated foliage at 25±1°C. When tested at 3×10⁵ conidia/cm², pathogenic activity of hyphomycetes towards noctuids showed high variability depending on both host-species and fungal isolate.M. brassicae was more susceptible to tested isolates than the other 3 noctuids. In contrast,S. littoralis was the most resistant species. The most active pathotypes had LT 50 values ranging from 2 to 3,5 days at the concentration of 3×10⁵ conidia/cm² and LD 50 values ranging from 10³ to 10⁴ conidia/cm² (mortality recorded at 6 days post exposure). According to these data, there were 5P. fumoso-roseus isolates (nos 13, 32, 39, 40 and 45) highly active againstM. brassicae, oneN. rileyi isolate (n^o 5) againstS. littoralis, oneP. fumoso-roseus isolate (n^o 32) againstS. frugiperda and oneM. anisopliae isolate (n^o 139) againstS. ipsilon. Bioassays establishing the high virulence of the FloridaN. rileyi isolate (n^o 5) to the Egyptian cottonworm and its pathogenic activity against the other tested noctuids, confirmed the interest for this fungal entomopathogen which has been demonstrated on noctuid populations in the southeastern United States. Moreover results of the host range assays of European isolates ofP. fumoso-roseus showed that this species appears to be an other potentially valuable microbial control agent against noctuid pests.

     

Illustrations pratiques — Pièges et artefacts/Trucs et astuces

Artifacts result from discrepancy between the estimated density values coming from the reconstructed CT image and the real value. They may come from many reasons (patient, device, algorithm, RX physical) and lead to deterioration of image quality and bad attenuation correction for SPECT or PET.     

Apoptose et spermatogenèse

Onset of spermatogenesis is associated with a wave of apoptosis, which limits its efficacy during the first cycles in most mammals. After the first cycles, the actual efficacy of spermatogenesis always remains below the theoretical yield. Among the germinal cells, spermatogonia are the main targets of physiological apoptosis. This physiological apoptosis partly depends on the relationships between germ cells and Sertoli cells. The impact of the Sertoli cell/germ cell number ratio on the efficacy of spermatogenesis is well accepted, the concept of density-dependent regulation in the seminiferous tubule was proposed in the early eighties. Since the steps of spermatogenesis require a continuous progression of the cell cycle rather than an arrest, germ cells might therefore be more sensitive to apoptosis. This may also lead to severe disturbances between proliferation and cell death. The first experiments designed to elucidate the mechanisms of germ cell apoptosis were based on hormonal deprivation or cryptorchidism. However, the link between hormonal or cellular action and cell survival remained to be established. Analysis of signal transduction pathways involved in germ cell apoptosis and their regulation were the next steps. The involvement of bcl-2 family genes has been confirmed, although the expression of some of its members remains more controversial. Data derived from overexpression of some genes (Bcl-2, Bcl-xl) or resulting from gene inactivation (Bax) at the testicular level have highlighted the role of these genes in the control of germ cell apoptosis and have also provided some evidence for the strict requirement for density-dependent regulation of spermatogenesis. More recently, variations in the pattern of expression of these genes or proteins helped to explain some of the discrepancies in the literature. The place of the Fas/Fas ligand system during the first cycle of spermatogenesis remains a matter of debate, with controversies concerning the precise site of expression of this oncogene and its receptor. Conversely, its role in the testis after chemotoxic or radiotoxic treatments is well established. However, the normal fertility of animals with a spontaneous inactivation of Fas or Fas L genes does not support a physiological role of these factors during spermatogenesis. While factors involved in TNF/TNF R1 (Tumor Necrosis Factor) are under study, some data have been reported concerning the role of TRAIL (TNFalpha Related Apoptosis Inducing Ligand) and its active or decoy receptors in the testis. Among the oncogenes which may modulate the apoptotic process, Kit/Stem Cell Factor is particularly interesting, as Kit is expressed in some germ cells and Leydig cells, whereas SCF is expressed by Sertoli cells. Its impact during gonadal development and in the survival and proliferation of differentiated spermatogonia has been clearly established. Using a transgenic mice model, in which the Kit gene was inactivated by the insertion of a nls-lacZ sequence in its first exon, we showed that one single copy of the gene was unable to sustain physiological spermatogenesis and fertility in male mice. Our results also suggest that the Kit gene might be expressed at different steps of spermatogenesis, with different signal transduction pathways and biological actions. Finally, analysis of the signal transduction pathways involved in testicular apoptosis and their mechanisms of control is one of the key steps to a better understanding of both impairment of spermatogenesis and the pathogenesis of certain germ cell tumours.     

Diptera Brachycera horse parasites in a stable/manège in northern Italy

The presence of tabanids and muscoid fly (Diptera Brachycera) parasites of horses in a stable/manège near Verona (Northern Italy) is reported. Tabanus quatuornotatus, T. glaucopis, T. exclusus, Hybomitra muehlfeldi, Haematopota pandazisi, Stomoxys calcitrans and Haematobia irritans were the blood-sucking species directly found on horses. Musca domestica, Ophyra sp. and Fannia canicularis were the flies most frequently collected by sticky traps in the stable.     

Le caryotype de l'Amphibien Urodèle Euproctus asper (Dugès)

Résumé Chez le Salamandridé Euproctus asper, le caryotype analysé à partir de testicules adultes et d'épiderme larvaire montre que le nombre chromosomique diploïde est de 24. Ces chromosomes se rangent en trois groupes principaux à l'intérieur desquels la plupart des éléments peuvent s'identifier individuellement grâce à leur indice centromérique.Le classement des chromosomes en trois groupes reste possible pour les figures haploïdes de 2^e division méïotique spermatocytaire. Dans ce dernier cas on peut encore, à l'intérieur de deux des groupes, identifier individuellement chacun des éléments.Il ne semble pas y avoir d'hétérochromosomes morphologiquement différenciés dans cette espèce.

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The karyotype of Euproctus asper (Urodela, Salamandridae) was analyzed from squash preparations of adult testes and larval epidermis. The diploid chromosome number is 24. These chromosomes can be classified into three groups. Most of the elements included in these groups can be identified individually by means of their length and arm-ratio. The classification into three groups remains possible for second meiotic division chromosomes. In the latter case, it is still possible to identify individually each chromosome in two of the three groups. There is no evidence of heteromorphic pairs in the present species.

     

Phéromones agrégeant les ouvrières de Myrmica rubra

The workers of Myrmica rubra aggregate around a source of one of their secretions, which can be called ‘alarm pheromone’, and also around workers of Lasius flavus. The mechanism of these aggregations differ.Both L. flavus workers and a solution in liquid paraffin of 3-octanol, one of the mandibular gland compounds, act as an arrestant for the workers of M. rubra. Both Dufour's gland secretion and a source of 3-octanone, the major compound of the mandibular gland secretion, are true attractants.The poison gland secretion, a mixture of 3-octanone and 3-octanol in liquid paraffin and a solution in liquid paraffin of 3-nonanone, a minor mandibular gland compound, all induce klinokinesis. The secretion of the mandibular glands and the secretion of the venom apparatus both cause positive klinokinesis and taxis. These locomotory reactions increase the probability that an object, marked by nest mates with these secretions, will be detected by several workers.When presented alone, 3-octanone is the only attractive compound in the mandibular gland secretion. However, a mixture of 3-octanone and 3-octanol (15 per cent of 3-octanol in the vapour phase) is detected more easily by the ants. The diffusion coefficients of the two compounds are different, and a mixture of these substances creates not only a quantitative but also a qualitative odour gradient. This may explain the synergy of the mixture.     

The Miocene mammal record of the Vallès-Penedès Basin (Catalonia)

The land mammal record of the Vallès-Penedès Basin (Catalonia, NE Spain) ranges from the early Miocene (Ramblian) to the late Miocene (Turolian), that is from about 20 to 7 Ma. Here we present an updated review of the mammal succession focusing on biochronology as well as on environmental and faunal changes. Based on faunal similarities with central Europe, we interpret this basin as a transitional zone between the forested environments of northern regions and the more arid landscapes of the inner Iberian Peninsula. The quality of the Vallès-Penedès record and its chronostratigraphic control is clearly better for the late Aragonian and the Vallesian (between 12.6–9.0 Ma), especially for small mammals. Therefore, we analyze small mammal diversity dynamics during this interval. Contrary to previous analyses, which found an abrupt extinction event coinciding with the early/late Vallesian boundary (the Vallesian Crisis), our results show that this pattern is due to uneven sampling. Instead, taxonomic richness slowly decreased since the late Vallesian as a result of a series of extinctions that mostly affected forest-dwelling taxa.     

La reine d'Apis mellifica les ouvrières pondeuses et les constructions cirières

Résumé Une cinquantaine d'abeilles, âgées de six jours, peut construire des alvéoles de cire en présence d'une reine vierge ou d'une reine féconde, ce nombre minimum s'élève à 200 avec une reine morte. En revanche, il faut atteindre une quantité importante d'insectes (10000 environ) pour obtenir des étirages de rayon sans reine. Cependant, la présence d'ouvrières pondeuses permet la construction des édifices de cire avec 5000 abeilles. On fait appel à une substance sécrétée par les reines ou bien les ouvrières pondeuses pour expliquer certains de ces phénomènes. Est-elle semblable à celle signalée parPain? Le parallélisme de nos résultats me porte à le croire.

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Summary 50 Bees, 6 years old, build combs in presence of mated or virgin queens; 200 insects can also construct in presence of a dead one. In return, 10,000queenless bees are necessary to assume the same task. But 5,000 laying workers can build combs. A queen substance is called upon to explain some of these phenomena.Is this andPain's ectohormone the same? The parallelism of our conclusions urge me to think so.

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Zusammenfassung In Anwesenheit einer unbegatteten oder begatteten Königin, zeigen 50 sechstägige Bienen eine deutliche Bautätigkeit. In Anwesenheit einer toten Königin müssen es schon 200 Bienen sein. Ohne Königin fängt erst mit 10000 Bienen die Bautätigkeit an. Mit eierlegenden Arbeiterinnen genügen doch 5000 Bienen. Die Erklärung dieser Tatsache wird in das Vorhandensein einer Substanz gesucht, welche durch die Königin oder durch eierlegenden Arbeiterinnen abgesondert wird. Man vermuttet daß diese Substanz dieselbe ist als diejenige die durchPain gefunden wurde.

     

Crassostrea gryphoides et C. gingensis (Schlotheim, 1813) deux expressions morphologiques d'une même espèce (Miocène, Bivalvia)

The assemblages of Crassostrea gryphoïdes of the Loupian's quarry is constitued of differents morphotypes which result of ecological effects (population density, locality and position in the assemblage). The selection of individuals with her life position shows two lots of Ostreidae the morphology of which is statistically different. The observations about Crassostrea of outcrops of Rhone's Valley and Touraine confirm the relations between position (liable to population's density) and morphology. The two types which are point out are often recognize as different species describe by E.F. von Schlotheim, 1813: Crassostrea gryphoïdes and Crassostrea gingensis. Therefore this two species must be consider as synonymous.