257 research outputs found
Daphnia (Ctenodaphnia) inopinata Popova, Petrusek, Kořínek, Mergeay, Bekker, Karabanov, Galimov, Neretina, Taylor & Kotov, 2016, sp. nov.
No full textDaphnia (Ctenodaphnia) inopinata sp. nov. (Figs. 4 D, 17–18) Daphnia similis -like cladoceran in Petrusek 2003: p. 12. Etymology. From Latin “inopinatus” = “unexpected”, referring to its unexpected finding in a suburb of a major metropolitan area. Type locality. Germany. Ponds in moorland northeast of the Fürst-Wrede-Kaserne barracks (Fröttmaninger Heide), Fröttmaning, Munich (N48.22°, E11.61°; altitude about 500 m). Type material. Holotype. Adult male, deposited at the collection of the Natural History Museum, London, U.K., NHMUK 2015.2924. Paratypes 10 parthenogenetic females, NHMUK 2015.2926-2935. 1 male, 5 females, Zoological Museum of M.V. Lomonosov Moscow State University, MGU Ml-144; 1 male, 7 females and 16 ephippia, personal collection of A.A. Kotov, AAK M-2610. Allotype. Parthenogenetic female, NHMUK 2015.2925. Other material studied. Some specimens from the type locality were used for genetic ivestigations and not saved. Short diagnosis. Parthenogenetic female. Body subovoid, a slight depression between head and rest of body (Fig. 17 A). Rostrum short, sharp, ventral margin of head without pre-ocular and post-ocular depressions, eye capsule located below the level of anteriormost point of head; ocellus present, bur minute. A projection from valves penetrates to about 1/3–1/2 of head shield length (Fig. 17 B). On outer side of postabdominal claw, the first and second (proximal) pectens consisting of relatively strong teeth, longest members approximately two times shorter than claw diameter; last tooth of the first pecten larger than others and additionally reinforced; third pecten consisting of numerous fine setules not reaching the tip of claw (Fig. 17 D, E). Tips of aesthetascs not projected beyond tip of rostrum (Fig. 17 B). On limb I setae 1–3 long, bearing short setules, seta 4 shorter than the former, with short setules (Fig. 17 F). Limb II–V as in other species of this group (Fig. 17 G). Ephippium. "D"-shaped, shell spine is not incorporated into ephippium (Fig. 4 D). Adult male. Body rectangular-rounded, a shallow depression between head and valves (Fig. 18 A). Head with a short rounded rostrum, lacking pre-ocular depression and almost lacking a post-ocular depression. Compound eye relative small, optical vesicle does not occupy whole anterior part of head (Fig. 18 B). First abdominal projection reduced, second projection small. Anal teeth present only in basal part of anal region, in anterior portion they are substituted by group of thin, short setules. On outer side of postabdominal claw, the first and second (proximal) pectens consisting of relatively strong teeth, last tooth of the first pecten is larger than others (Fig. 18 E, F). Antenna I long, antennular sensory located distally on end of antenna I body; flagellum long, bisegmented, its distal segment setulated (Fig. 18 C). On limb I anterior setae 2, 3 and 4 smaller that these in female and supplied with longer setules (Fig. 18 H–J). Limb V with a small additional seta on distal portion of exopodite (Fig. 18 K). Description. Adult parthenogenetic female. General. Body almost transparent, body depth/length (without shell spine) = 0.54–0.65, subovoid in lateral view, with maximum height in middle of valves, a shallow depression between head and rest of body, dorsal margin somewhat convex. Postero-dorsal angle in adults with a relatively short caudal spine, ventral margin regularly convex (Fig. 17 A). Head with a relatively short, sharp rostrum; posterior margin of head with a low mound in the basal part, prerostral fold absent; ventral margin of head without any pre-ocular and post-ocular depressions, valve dorsal contour lies somewhat above head. Compound eye relatively small, ocellus distinct, although minute, located closer to the compoun eye than to base A1. Head shield with slightly projected, blunt fornices, a projection from valves penetrates to about 1/3–1/2 of its length (Fig. 17 B). Carapace slightly convex dorsally, free edge uniformly convex. spinules present on whole dorsal margin and on posterior half of ventral margin. A group of relatively long setae in middle of ventral margin submarginally, short setae present on the postero-ventral edge of valve, setules between them absent (Fig. 17 C). Abdomen relatively short, consisting of four segments, the first (basalmost) abdominal segment with a relatively short (somewhat longer than postabdominal claw) process, slightly bent forward; second segment with a small (shorter than postabdominal claw) process bent backward, the third segment with a very low, mound-like process, covered by transverse rows of minute setules; the fourth segment without a process. Postabdomen tapering distally, with ventral margin straight. Preanal margin almost straight, with series of minute setules. Preanal and postanal angle not expressed. Anal teeth not numerous, slightly curved. Postabdominal setae approximately equal to length of preanal edge, their distal and proximal segments are almost identical. Postabdominal claw is slightly bent, with a pointed tip. Three pectens on its inner sides. The first and the second pectens are composed of longer teeth, with the longest members approximately two times shorter than claw diameter, last tooth of the first pecten larger than others and additionally reinforced; the third pecten consists of thin short setules and that fail to reach the tip of the claw (Fig. 17 D–E). Antenna I is a conical tubercle with nine terminal aesthetascs and tips not projecting beyond tip of rostrum, antennular sensory seta arises from base of mound of the antenna I and reaching tip of mound (Fig. 17 B). Antenna II relatively long, length of apical setae approximately equal to the length of the branches. Antenna formula: setae1–1–3 / 0–0–1–3. Limbs I–V, as in D. similoides. Ephippium. "D"-shaped, shell spine is not incorporated into ephippium (Fig. 4 D). Adult male. General. Body elongated, body depth/length (without shell spine) = 0.44–0.45, rectangularrounded. Dorsal margin almost straight, slightly elevated above head; shallow depression between head and valves; postero-dorsal angle distinct, with a short caudal spine; posterior margin almost straight; postero-ventral angle broadly rounded, ventral margin with a depression in middle and a projection in anterior portion. spinules cover only posterior half of dorsal and ventral valve margin (Fig. 18 A, C). Head rounded, with a short rounded rostrum, convex ventral margin, lacking pre-ocular depression and almost lacking a post-ocular depression. Compound eye relatively small, optical vesicle does not occupy whole anterior part of head, ocellus small (Fig. 18 B). Carapace. Ventral edge with a projection in anterior portion, bearing mumerous, relatively long setae, then a small depression, also supplied by somewhat shorter setae. On postero-ventral portion, shorther setae without setules between them. Abdomen. First abdominal projection reduced; second projection small; third and fourth reduced. Postabdomen with a straight dorsal margin; ill-defined preanal angle and smooth postanal angle; distal portion as a short tube; dorsal margin almost straight in preanal region; gonopore opens subdistally, on a reduced genital papilla. Anal teeth present only in basal part of anal region, in anterior portion they are substituted by group of thin, short setules. Postabdominal claw thick, with a pointed end. The first two pectens on postabdominal claw consist of long teeth. First tooth of the first pecten particularly strong (Fig. 18 E–G). Antenna I long, somewhat widening distally, without denticles distally near aesthetascs. Nine aesthetascs short. Antennular sensory setae located distally on end of antenna I body, the former shorter than aesthetascs. Length of flagellum about half body length of the antenna I. The distal segment of flagellum is covered with short setules (Fig. 18 D). Antenna II relatively larger as compared with female. Limb I. ODL large, bearing a short seta and a very large seta, supplied with minute setules distally; IDL with a bent copulatory hook, and two setae of very different size; in contrast to female, setae 2, 3 and 4 shorter than those in female and supplied with long, fine setules (Fig. 18 H–J). Limb V. In general as in female, but there is an additional (third) small seta on exopodite (Fig. 18 K). Size. Adult females 1.54–2.2 mm, adult males 1.19–1.38 mm. Distribution. Daphnia (Ctenodaphnia) inopinata sp. nov. is known from pools in a single area of a military training ground in Germany. Comments. At this moment little information is available on the geographic range of this species. Considering that no other locality of this taxon has been so far discovered in Central Europe, the species could have been recently introduced to Germany by anthropogenic activities (as discussed in Petrusek 2003). But it could also be a specific European lineage that eluded discovery, as with D. hrbaceki Juračka, Kořínek & Petrusek, 2010. Small pools attracted less attention of European hydrobiologists as compared to large lakes. Differential diagnosis. Taxonomically informative morphological differences among females of the D. similis group remain undetected. Therefore, only males are useful for the differentiation of species. Males of D. inopinata sp. nov. have anal teeth on postabdomen reduced in size and number (in contrast to D. similis s. str.), compound eye relatively small, and anteriormost portion of head without a dome (in contrast to D. sinensis), distalmost anal teeth minute and additional seta on exopodite V present (in contrast to D. similoides).Published as part of Popova, Ekaterina V., Petrusek, Adam, Kořínek, Vladimír, Mergeay, Joachim, Bekker, Eugeniya I., Karabanov, Dmitry P., Galimov, Yan R., Neretina, Tatyana V., Taylor, Derek J. & Kotov, Alexey A., 2016, Revision of the Old World Daphnia (Ctenodaphnia) similis group (Cladocera: Daphniidae), pp. 1-40 in Zootaxa 4161 (1) on pages 28-31, DOI: 10.11646/zootaxa.4161.1.1, http://zenodo.org/record/27223
Etude de la diversit\ue9 enzymatique des microorganismes du sol par l'approche m\ue9tagenomique
No full textHorizontal gene transfer in the environment and the significance of broad host range plasmids
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A potential role for bacterial endophytes in phytoremediation of heavy metal contaminated soils
No full textThis thesis aims to study the potential contribution of heavy metal resistant endophytic bacteria on heavy metal uptake and translocation processes by their host plant. The extensive study of bacterial heavy metal resistance mechanisms showed that metal bioprecipitation processes near the bacterial cell wall are often found to be a consequence of efflux based systems that reduce the bioavailable metal concentration present. Heavy metal resistant endophytic bacteria with a similar behaviour would possibly result in a lowered heavy metal bioavailability that consequently would lead to a lowered heavy metal toxicity or an improved heavy metal accumulation within the host plant. Based on this concept, new strategies to improve phytoremediation would be developed.Deze thesis heeft als doel de potentiële bijdrage van zware metalen resistente endofytische bacteriën op de zware metalen opname en translocatieprocessen van hun gastheerplant te bestuderen. De intensieve studie van de bacteriële zware metalen resistentiemechanismen toonde immers aan dat metaal bioprecipitatie processen ter hoogte van de bacteriële celwand dikwijls optreden als gevolg van efflux gebaseerde systemen die de aanwezige biologisch beschikbare zware metalen reduceren. In analogie hiermee zou de aanwezigheid van zware metaal resistente endofyten kunnen resulteren in een verlaagde biologische beschikbaarheid van de zware metalen in de plant wat tot een verminderde zware metaal toxiciteit of verbeterde zware metaalaccumulatie in de plant kan leiden. Hierop gebaseerd kunnen strategieën voor een verbeterde fytoremediatie van zware metalen worden ontwikkeld
A potential role for bacterial endophytes in phytoremediation of heavy metal contaminated soils
No full textThis thesis aims to study the potential contribution of heavy metal resistant endophytic bacteria on heavy metal uptake and translocation processes by their host plant. The extensive study of bacterial heavy metal resistance mechanisms showed that metal bioprecipitation processes near the bacterial cell wall are often found to be a consequence of efflux based systems that reduce the bioavailable metal concentration present. Heavy metal resistant endophytic bacteria with a similar behaviour would possibly result in a lowered heavy metal bioavailability that consequently would lead to a lowered heavy metal toxicity or an improved heavy metal accumulation within the host plant. Based on this concept, new strategies to improve phytoremediation would be developed.Deze thesis heeft als doel de potentiële bijdrage van zware metalen resistente endofytische bacteriën op de zware metalen opname en translocatieprocessen van hun gastheerplant te bestuderen. De intensieve studie van de bacteriële zware metalen resistentiemechanismen toonde immers aan dat metaal bioprecipitatie processen ter hoogte van de bacteriële celwand dikwijls optreden als gevolg van efflux gebaseerde systemen die de aanwezige biologisch beschikbare zware metalen reduceren. In analogie hiermee zou de aanwezigheid van zware metaal resistente endofyten kunnen resulteren in een verlaagde biologische beschikbaarheid van de zware metalen in de plant wat tot een verminderde zware metaal toxiciteit of verbeterde zware metaalaccumulatie in de plant kan leiden. Hierop gebaseerd kunnen strategieën voor een verbeterde fytoremediatie van zware metalen worden ontwikkeld
Mechanisms of gold biomineralization in the bacterium Cupriavidus metallidurans
No full textWhile the role of microorganisms as main drivers of metal mobility and mineral formation under Earth surface conditions is now widely accepted, the formation of secondary gold (Au) is commonly attributed to abiotic processes. Here we report that the biomineralization of Au nanoparticles in the metallophillic bacterium Cupriavidus metallidurans CH34 is the result of Au-regulated gene expression leading to the energy-dependent reductive precipitation of toxic Au(III)-complexes. C. metallidurans, which forms biofilms on Au grains, rapidly accumulates Au(III)-complexes from solution. Bulk and microbeam synchrotron X-ray analyses revealed that cellular Au accumulation is coupled to the formation of Au(I)-S complexes. This process promotes Au toxicity and C. metallidurans reacts by inducing oxidative stress and metal resistances gene clusters (including a Au-specific operon) to promote cellular defense. As a result, Au detoxification is mediated by a combination of efflux, reduction, and possibly methylation of Au-complexes, leading to the formation of Au(I)-C-compounds and nanoparticulate Au(0). Similar particles were observed in bacterial biofilms on Au grains, suggesting that bacteria actively contribute to the formation of Au grains in surface environments. The recognition of specific genetic responses to Au opens the way for the development of bioexploration and bioprocessing tools.Frank Reith, Barbara Etschmann, Cornelia Grosse, Hugo Moors, Mohammed A. Benotmane, Pieter Monsieurs, Gregor Grass, Christian Doonan, Stefan Vogt, Barry Lai, Gema Martinez-Criado, Graham N. George, Dietrich H. Nies, Max Mergeay, Allan Pring, Gordon Southam and Joël Brugge
A pragmatic approach for integrating molecular tools into biodiversity conservation
No full textMolecular tools are increasingly applied for assessing and monitoring biodiversity and informing conservation action. While recent developments in genetic and genomic methods provide greater sensitivity in analysis and the capacity to address new questions, they are not equally available to all practitioners: There is considerable bias across institutions and countries in access to technologies, funding, and training. Consequently, in many cases, more accessible traditional genetic data (e.g., microsatellites) are still utilized for making conservation decisions. Conservation approaches need to be pragmatic by tackling clearly defined management questions and using the most appropriate methods available, while maximizing the use of limited resources. Here we present some key questions to consider when applying the molecular toolbox for accessible and actionable conservation management. Finally, we highlight a number of important steps to be addressed in a collaborative way, which can facilitate the broad integration of molecular data into conservation.Fil: Bertola, Laura D.. Universidad de Copenhagen; DinamarcaFil: Brüniche Olsen, Anna. Universidad de Copenhagen; DinamarcaFil: Kershaw, Francine. Natural Resources Defense Council; Estados UnidosFil: Russo, Isa Rita M.. Cardiff University; Reino UnidoFil: MacDonald, Anna J.. Australian Antarctic Division; AustraliaFil: Sunnucks, Paul. Monash University; AustraliaFil: Bruford, Michael W.. Cardiff University; Reino UnidoFil: Cadena, Carlos Daniel. Universidad de los Andes; ColombiaFil: Ewart, Kyle M.. University Of Sydney; AustraliaFil: de Bruyn, Mark. Griffith University; AustraliaFil: Eldridge, Mark D. B.. Australian Museum; AustraliaFil: Frankham, Richard. Macquarie University; AustraliaFil: Guayasamin, Juan M.. Universidad San Francisco de Quito; EcuadorFil: Grueber, Catherine E.. University Of Sydney; AustraliaFil: Hoareau, Thierry B.. University Of Pretoria; SudáfricaFil: Hoban, Sean. Center for Tree Science; Estados UnidosFil: Hohenlohe, Paul A.. University of Idaho; Estados UnidosFil: Hunter, Margaret E.. United States Geological Survey; Estados UnidosFil: Kotze, Antoinette. South African National Biodiversity Institute; SudáfricaFil: Kuja, Josiah. Universidad de Copenhagen; DinamarcaFil: Lacy, Robert C.. Chicago Zoological Society; Estados UnidosFil: Laikre, Linda. Stockholms Universitet; SueciaFil: Lo, Nathan. University Of Sydney; AustraliaFil: Meek, Mariah H.. Michigan State University; Estados UnidosFil: Mergeay, Joachim. Katholikie Universiteit Leuven; BélgicaFil: Mittan Moreau, Cinnamon. Michigan State University; Estados UnidosFil: Paez Vacas, Monica Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina. Universidad Tecnologica Indoamerica.; EcuadorFil: Pierson, Jennifer. Australian Wildlife Conservancy; AustraliaFil: Steeves, Tammy. University of Canterbury; Nueva ZelandaFil: Vernesi, Cristiano. Instituto Agrario San Michele all'Adige Fondazione Edmund Mach; Itali
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